BACKGROUND:Promoting skin wound healing is a huge challenge facing global public health.To promote faster and higher-quality wound healing,it is necessary to explore more advantageous dressings to address this problem.OBJECTIVE:To investigate the hemostatic properties of acellular dermal matrix hydrogel and its effect on skin wound healing.METHODS:(1)Acellular dermal matrix hydrogel was prepared,and the differences in microscopic morphology and main components between it and acellular dermal matrix were analyzed.(2)Acellular dermal matrix hydrogel and chitosan hydrogel were used to cover the femoral artery puncture site of rats,and the bleeding quality and coagulation time were recorded.Acellular dermal matrix hydrogel and chitosan hydrogel were mixed with rat anticoagulated blood,and the coagulation index within 30 minutes was detected.(3)A full-thickness skin defect model with a diameter of 12 mm was made on the back of 18 SD rats,and they were randomly divided into 3 groups,with 6 rats in each group:the model group used PBS to clean the wound,and the control group and the experimental group used chitosan hydrogel and acellular dermal matrix hydrogel to cover the wound,respectively.The hydrogel dressing was changed every day,and the treatment was continued for 14 days,and the wound healing was observed.On day 3 after modeling,immunofluorescence staining of inducible nitric oxide synthase(M1 macrophages)and CD206(M2 macrophages)was performed on the wound surface.On day 14 after modeling,hematoxylin-eosin staining,Masson staining,and CD31 immunohistochemical staining were performed on the wound surface.RESULTS AND CONCLUSION:(1)Scanning electron microscopy revealed that the acellular dermal matrix hydrogel had a porous structure,and the Fourier transform infrared spectrum showed that it had the same main components as the acellular dermal matrix.(2)Both acellular dermal matrix hydrogel and chitosan hydrogel had obvious hemostatic ability in vivo.In the in vitro coagulation experiments,the coagulation index of acellular dermal matrix hydrogel was significantly higher than that of chitosan hydrogel.(3)In the rat skin full-thickness defect model,both acellular dermal matrix hydrogel and chitosan hydrogel could improve the wound healing rate.Hematoxylin-eosin and Masson staining results showed that acellular dermal matrix hydrogel could reduce the infiltration of inflammatory cells in the center of the wound.Both acellular dermal matrix hydrogel and chitosan hydrogel could decrease scar width and increase collagen deposition rate.CD31 immunohistochemical staining results showed that both hydrogels could promote angiogenesis in the wound site.Immunofluorescence staining results showed that both hydrogels could reduce the proportion of M1 macrophages and increase the proportion of M2 macrophages,and the effect of acellular dermal matrix hydrogel was stronger than that of chitosan hydrogel.(4)The results show that the acellular dermal matrix hydrogel has good hemostatic properties and the ability to promote wound healing.

BACKGROUND:Promoting skin wound healing is a huge challenge facing global public health.To promote faster and higher-quality wound healing,it is necessary to explore more advantageous dressings to address this problem.OBJECTIVE:To investigate the hemostatic properties of acellular dermal matrix hydrogel and its effect on skin wound healing.METHODS:(1)Acellular dermal matrix hydrogel was prepared,and the differences in microscopic morphology and main components between it and acellular dermal matrix were analyzed.(2)Acellular dermal matrix hydrogel and chitosan hydrogel were used to cover the femoral artery puncture site of rats,and the bleeding quality and coagulation time were recorded.Acellular dermal matrix hydrogel and chitosan hydrogel were mixed with rat anticoagulated blood,and the coagulation index within 30 minutes was detected.(3)A full-thickness skin defect model with a diameter of 12 mm was made on the back of 18 SD rats,and they were randomly divided into 3 groups,with 6 rats in each group:the model group used PBS to clean the wound,and the control group and the experimental group used chitosan hydrogel and acellular dermal matrix hydrogel to cover the wound,respectively.The hydrogel dressing was changed every day,and the treatment was continued for 14 days,and the wound healing was observed.On day 3 after modeling,immunofluorescence staining of inducible nitric oxide synthase(M1 macrophages)and CD206(M2 macrophages)was performed on the wound surface.On day 14 after modeling,hematoxylin-eosin staining,Masson staining,and CD31 immunohistochemical staining were performed on the wound surface.RESULTS AND CONCLUSION:(1)Scanning electron microscopy revealed that the acellular dermal matrix hydrogel had a porous structure,and the Fourier transform infrared spectrum showed that it had the same main components as the acellular dermal matrix.(2)Both acellular dermal matrix hydrogel and chitosan hydrogel had obvious hemostatic ability in vivo.In the in vitro coagulation experiments,the coagulation index of acellular dermal matrix hydrogel was significantly higher than that of chitosan hydrogel.(3)In the rat skin full-thickness defect model,both acellular dermal matrix hydrogel and chitosan hydrogel could improve the wound healing rate.Hematoxylin-eosin and Masson staining results showed that acellular dermal matrix hydrogel could reduce the infiltration of inflammatory cells in the center of the wound.Both acellular dermal matrix hydrogel and chitosan hydrogel could decrease scar width and increase collagen deposition rate.CD31 immunohistochemical staining results showed that both hydrogels could promote angiogenesis in the wound site.Immunofluorescence staining results showed that both hydrogels could reduce the proportion of M1 macrophages and increase the proportion of M2 macrophages,and the effect of acellular dermal matrix hydrogel was stronger than that of chitosan hydrogel.(4)The results show that the acellular dermal matrix hydrogel has good hemostatic properties and the ability to promote wound healing.

As an important structure for maintaining the homeostasis of the central nervous system, the meningeal lymphatic vessels can clear abnormal proteins and metabolic wastes from the brain. Numerous studies have shown that meningeal lymphatic vessel dysfunction is closely related to the pathological process of Alzheimer′s disease. Enhancing the drainage function of meningeal lymphatic vessels may provide an innovative strategy for the treatment of the disease. This article systematically expounds the structure, function and "space-dependent differences" of meningeal lymphatic vessels, deeply explores their role in the pathogenesis of Alzheimer′s disease, and investigates the intervention measures to improve the function of meningeal lymphatic vessels, aiming to open up new ideas for the prevention and treatment of Alzheimer′s disease.

Objective:To investigate the current situation of water-borne endemic fluorosis in Anhui Province, and provide basic data for the adjusting the prevention and control measures.Methods:Using cross-sectional survey method, all villages in the water-borne endemic fluorosis areas were investigated in Anhui Province from 2019 to 2022. In water-borne endemic fluorosis village, the situation of water improvement project and the fluoride level of drinking water were investigated, and dental fluorosis of all children aged 8 - 12 was examined. The criteria for determining the achievement of control targets for water-borne endemic fluorosis in affected counties were based on the "Evaluation Measures for Control and Elimination of Key Endemic Diseases (2019 Edition)".Results:From 2019 to 2022, the rate of water improvement village in water-borne endemic fluorosis areas were 88.47% (1 527/1 726), 100% (1 726/1 726), 100% (1 726/1 726) and 100% (1 726/1 726), respectively. The qualified proportion of water fluoride in water-borne endemic fluorosis villages was 33.84% (584/1 726), 63.09% (1 089/1 726), 70.74% (1 221/1 726) and 74.33% (1 283/1 726), respectively. The prevalence rates of dental fluorosis in children aged 8 - 12 were 25.48% (45 461/178 440), 15.78% (27 959/177 200), 13.68% (23 505/171 880) and 12.66% (23 315/184 200), respectively. The proportion of affected counties that had achieved the control target of water-borne endemic fluorosis was 16% (4/25), 60% (15/25), 36% (9/25) and 40% (10/25), respectively.Conclusions:The water-borne endemic fluorosis areas in Anhui Province have improved the water fluoride qualification rate and reduced the incidence of fluorosis in children through prevention and control measures such as water improvement and fluoride reduction. However, the prevention and control efforts in key areas and counties need to be further improved.

Objective To observe the differences in gut microbiota in chronic unpredictable mild stress(CUMS)-induced depression model rats of both sexes,and to provide experimental evidence for exploring sex differences in depression onset.Methods Thirty-two healthy SD rats were divided randomly into four groups based on sex:Male control group(Control-M),Female control group(Control-F),Male model group(Model-M),and Female model group(Model-F)(n=8 rats per group).Rats in the control groups were fed without stimulation,while rats in the model groups were stimulated using the 28 d CUMS-induced depression method.After successful modeling,fresh feces were collected from all rats for high-throughput 16S rRNA sequencing.Behavioral observations were also conducted before and after preparing the model.Results The result of sucrose-preference,open-field,and forced-swimming tests differed significantly between the control and model groups.The result of the sucrose-preference test also differed between the sexes,while there was no difference in the open-field or forced-swimming test between the sexes.The α and β diversity of the gut microbiota genera showed an upward trend in the CUMS group compared with the control group.The ratio of Firmicutes/Bacteroidetes and the richness of the Roseburia and Lachnospiraceae_NK4A136_group were decreased in male rats but showed an increasing trend in female rats.Conclusions The ratio of Firmicutes/Bacteroidetes in the gut microbiota may be a key factor affecting the difference in the onset of depression between males and females,while the Roseburia and Lachnospiraceae_NK4A136_group be potential factors in correcting the gut microbiota and improving the symptoms of depression.

Objective:A two-sample bidirectional Mendelian randomization (MR) analysis was used to analyze the risk factors related to sunburn.Methods:Data were downloaded from the Gene-Wide Association Studies (GWAS) of the IEU Open GWAS project, and a two-sample bidirectional MR was conducted. In the forward MR analysis, the exposure factors were skin color, ease of skin tanning, skin pigmentation, facial aging, atopic dermatitis, contact dermatitis, urticaria, and education attainment, while the outcome factor was sunburn. In the reverse MR analysis, the exposure factor was sunburn, while the outcome factors were skin color, ease of skin tanning, skin pigmentation, facial aging, atopic dermatitis, contact dermatitis, urticaria, and education attainment. The data were analyzed using the "TwoSampleMR" package in R version 4.2.3. The result of the MR analysis were interpreted using the odds ratio ( OR) and the corresponding 95% confidence interval (95% CI), and a P-value <0.05 was considered statistically significant. In the analysis, we set a significance threshold of P-value<5×10 -8 (if sufficient instrumental variables cannot be obtained, the threshold will be adjusted to P-value<5×10 -6), eliminated linkage disequilibrium (with R2<0.001 and within a regional range of 10 000 kb), and screened single nucleotide polymorphisms (SNPs) that were significantly related to the research content, which would be set in the analysis as instrumental variables (IVs). For eligible IVs, a MR was conducted using the MR Egger, Weighted median, Inverse variance weighted (IVW), Simple mode, and Weighted mode method to explore the causal relationships between sunburn and various factors. The result obtained by the IVW method were taken as the main outcome indicator and summarized into a forest plot, while other method were used to supplement the IVW result. The heterogeneity of the IVs was evaluated by the Cochran Q-test. The direction of the causal effect and heterogeneity were evaluated through the scatter plot. The sensitivity of the result was analyzed by the leave-one-out test. The funnel plot was used to assess the potential bias. Results:9 851 867 SNPs related to skin color, 9 851 867 SNPs related to ease of skin tanning, 11 972 414 SNPs related to skin pigmentation, 9 851 867 SNPs related to facial aging, 16 121 213 SNPs related to atopic dermatitis, 24 191 078 SNPs related to contact dermatitis, 24 187 496 SNPs related to urticaria, 11 972 619 SNPs related to education attainment were obtained from the GWAS database. A total of 11 976 212 SNPs were obtained from the sunburn dataset. In the forward MR analysis, the IVW result showed a significant negative correlation between skin color and sunburn ( OR=0.68, 95% CI: 0.66-0.70, P<0.001); and a significant positive correlation between the ease of skin tanning, skin pigmentation, facial aging, atopic dermatitis, contact dermatitis, education attainment, and sunburn (ease of skin tanning: OR=1.30, 95% CI: 1.29-1.32, P<0.001; skin pigmentation: OR=1.76, 95% CI: 1.66-1.87, P<0.001; facial aging: OR=2.25, 95% CI: 1.67-3.04, P<0.001; atopic dermatitis: OR=1.02, 95% CI: 1.00-1.03, P=0.010; contact dermatitis: OR=1.01, 95% CI: 1.00-1.01, P=0.031; education attainment: OR=1.29, 95% CI: 1.22-1.36, P<0.001); while urticaria was not statistically significant ( P=0.056). The Cochran Q-test and scatter plot showed that there was a significant negative correlation between skin color and sunburn and a positive correlations between the ease of skin tanning, skin pigmentation, facial aging, atopic dermatitis, contact dermatitis, education attainment and sunburn. There was some heterogeneity among the IVs in research. The result of the leave-one-out test showed that no SNPs had a distinct impact on the causal effect, and the result of the forward MR analysis were relatively stable. The result of the funnel plot showed that the included SNPs were symmetrically distributed, and there was no potential bias in the result. In the reverse MR analysis, the IVW result showed a significant negative correlation between sunburn and skin color ( OR=0.16, 95% CI: 0.12-0.21, P<0.001); and a significant positive correlation between sunburn and ease of skin tanning, skin pigmentation, facial aging (ease of skin tanning: OR=26.78, 95% CI: 20.52-34.93, P<0.001; skin pigmentation: OR=3.12, 95% CI: 2.57-3.78, P<0.001; facial aging: OR=1.30, 95% CI: 1.24-1.37, P<0.001); while atopic dermatitis ( P=0.477), contact dermatitis ( P=0.318), urticaria ( P=0.328) and education attainment ( P=0.627) as outcome factors were not statistically significant. The Cochran Q-test and scatter plot showed that there was a significant negative correlation between sunburn and skin color and a positive correlations between sunburn and ease of skin tanning, skin pigmentation, facial aging. There was some heterogeneity among the IVs in research. The result of the leave-one-out test showed that no SNPs had a distinct impact on the causal effect, and the result of the reverse MR analysis were relatively stable. The result of the funnel plot showed that the included SNPs were symmetrically distributed, and there was no potential bias in the result . Conclusions:Skin color and sunburn are protective factors against each other; ease of skin tanning, skin pigmentation, and facial aging are bidirectional risk factors of sunburn; atopic dermatitis, contact dermatitis, and education attainment are risk factors of sunburn.

Objective:To investigate the protective effect of moxibustion on joints and its influence on the expression levels of S100 calcium binding protein A8(S100A8),S100 calcium binding protein A9(S100A9),serum amyloid A1(SAA1),and related inflammatory factors in rats with adjuvant arthritis(AA).Methods:Forty Wistar rats were randomly divided into a normal group,a model group,a moxibustion group,and a medication group,with 10 rats in each group.Except for the normal group,AA models were established in the other three groups by exposing rats to wind-cold-dampness environmental conditions combined with complete Freund's adjuvant.After successful modeling,the moxibustion group received moxibustion intervention,while the medication group was administered tripterygium glycosides tablets via oral gavage.The normal and model groups underwent similar handling and fixation without additional interventions.After 15 d of intervention,hematoxylin-eosin staining was used to assess pathological changes in the knee joint synovial membrane.Western blotting was performed to detect the protein expression of S100A8,S100A9,and SAA1 in the synovial tissue.Enzyme-linked immunosorbent assay was used to measure the serum levels of interferon(IFN)-γ,interleukin(IL)-6,and IL-23.Results:Compared to the normal group,the model group exhibited significantly increased protein expression of S100A8,S100A9,and SAA1 in the knee joint synovial tissue,as well as elevated serum levels of IFN-γ,IL-6,and IL-23(P<0.01).Histopathological analysis revealed marked synovial hyperplasia and extensive infiltration of inflammatory cells in the model group.Compared to the model group,both the moxibustion and medication groups showed significant reductions in the protein expression of S100A8,S100A9,and SAA1 in the synovial tissue,as well as decreased serum levels of IFN-γ,IL-6,and IL-23(P<0.01).Additionally,synovial tissue in these two groups displayed minimal hyperplasia and only mild inflammatory cell infiltration.Notably,compared to the moxibustion group,the medication group exhibited significantly higher protein expression of S100A9 in the synovial tissue(P<0.05),while no significant differences were observed in the expression of S100A8,SAA1,or serum levels of IFN-γ,IL-6,and IL-23(P>0.05).Both intervention groups showed comparable degrees of synovial inflammation,clear tissue structure,and no obvious hyperplasia.Conclusion:Moxibustion can alleviate joint swelling and reduce inflammatory responses in AA rats.Its mechanism may involve regulating the protein expression of S100A8,S100A9,and SAA1 in the knee joint synovial tissue.

Objective:A two-sample bidirectional Mendelian randomization (MR) analysis was used to analyze the risk factors related to sunburn.Methods:Data were downloaded from the Gene-Wide Association Studies (GWAS) of the IEU Open GWAS project, and a two-sample bidirectional MR was conducted. In the forward MR analysis, the exposure factors were skin color, ease of skin tanning, skin pigmentation, facial aging, atopic dermatitis, contact dermatitis, urticaria, and education attainment, while the outcome factor was sunburn. In the reverse MR analysis, the exposure factor was sunburn, while the outcome factors were skin color, ease of skin tanning, skin pigmentation, facial aging, atopic dermatitis, contact dermatitis, urticaria, and education attainment. The data were analyzed using the "TwoSampleMR" package in R version 4.2.3. The result of the MR analysis were interpreted using the odds ratio ( OR) and the corresponding 95% confidence interval (95% CI), and a P-value <0.05 was considered statistically significant. In the analysis, we set a significance threshold of P-value<5×10 -8 (if sufficient instrumental variables cannot be obtained, the threshold will be adjusted to P-value<5×10 -6), eliminated linkage disequilibrium (with R2<0.001 and within a regional range of 10 000 kb), and screened single nucleotide polymorphisms (SNPs) that were significantly related to the research content, which would be set in the analysis as instrumental variables (IVs). For eligible IVs, a MR was conducted using the MR Egger, Weighted median, Inverse variance weighted (IVW), Simple mode, and Weighted mode method to explore the causal relationships between sunburn and various factors. The result obtained by the IVW method were taken as the main outcome indicator and summarized into a forest plot, while other method were used to supplement the IVW result. The heterogeneity of the IVs was evaluated by the Cochran Q-test. The direction of the causal effect and heterogeneity were evaluated through the scatter plot. The sensitivity of the result was analyzed by the leave-one-out test. The funnel plot was used to assess the potential bias. Results:9 851 867 SNPs related to skin color, 9 851 867 SNPs related to ease of skin tanning, 11 972 414 SNPs related to skin pigmentation, 9 851 867 SNPs related to facial aging, 16 121 213 SNPs related to atopic dermatitis, 24 191 078 SNPs related to contact dermatitis, 24 187 496 SNPs related to urticaria, 11 972 619 SNPs related to education attainment were obtained from the GWAS database. A total of 11 976 212 SNPs were obtained from the sunburn dataset. In the forward MR analysis, the IVW result showed a significant negative correlation between skin color and sunburn ( OR=0.68, 95% CI: 0.66-0.70, P<0.001); and a significant positive correlation between the ease of skin tanning, skin pigmentation, facial aging, atopic dermatitis, contact dermatitis, education attainment, and sunburn (ease of skin tanning: OR=1.30, 95% CI: 1.29-1.32, P<0.001; skin pigmentation: OR=1.76, 95% CI: 1.66-1.87, P<0.001; facial aging: OR=2.25, 95% CI: 1.67-3.04, P<0.001; atopic dermatitis: OR=1.02, 95% CI: 1.00-1.03, P=0.010; contact dermatitis: OR=1.01, 95% CI: 1.00-1.01, P=0.031; education attainment: OR=1.29, 95% CI: 1.22-1.36, P<0.001); while urticaria was not statistically significant ( P=0.056). The Cochran Q-test and scatter plot showed that there was a significant negative correlation between skin color and sunburn and a positive correlations between the ease of skin tanning, skin pigmentation, facial aging, atopic dermatitis, contact dermatitis, education attainment and sunburn. There was some heterogeneity among the IVs in research. The result of the leave-one-out test showed that no SNPs had a distinct impact on the causal effect, and the result of the forward MR analysis were relatively stable. The result of the funnel plot showed that the included SNPs were symmetrically distributed, and there was no potential bias in the result. In the reverse MR analysis, the IVW result showed a significant negative correlation between sunburn and skin color ( OR=0.16, 95% CI: 0.12-0.21, P<0.001); and a significant positive correlation between sunburn and ease of skin tanning, skin pigmentation, facial aging (ease of skin tanning: OR=26.78, 95% CI: 20.52-34.93, P<0.001; skin pigmentation: OR=3.12, 95% CI: 2.57-3.78, P<0.001; facial aging: OR=1.30, 95% CI: 1.24-1.37, P<0.001); while atopic dermatitis ( P=0.477), contact dermatitis ( P=0.318), urticaria ( P=0.328) and education attainment ( P=0.627) as outcome factors were not statistically significant. The Cochran Q-test and scatter plot showed that there was a significant negative correlation between sunburn and skin color and a positive correlations between sunburn and ease of skin tanning, skin pigmentation, facial aging. There was some heterogeneity among the IVs in research. The result of the leave-one-out test showed that no SNPs had a distinct impact on the causal effect, and the result of the reverse MR analysis were relatively stable. The result of the funnel plot showed that the included SNPs were symmetrically distributed, and there was no potential bias in the result . Conclusions:Skin color and sunburn are protective factors against each other; ease of skin tanning, skin pigmentation, and facial aging are bidirectional risk factors of sunburn; atopic dermatitis, contact dermatitis, and education attainment are risk factors of sunburn.

Objective:To analyze the gallbladder morphology in ultrasound examinations of children with biliary atresia, classify them accordingly, and compare the gallbladder size of different types of patients and healthy infants.Methods:Clinical data of 711 cases with biliary atresia treated at the Department of General Surgery at the Capital Center for Children's Health, Capital Medical University from January 2017 to July 2022 were retrospectively analyzed, including 407 males and 304 females, aged (46.5±26.9) days. Additionally, 106 healthy infants recruited from the same hospital between January 2024 and March 2024 were included in the control group, including 60 males and 46 females, aged (48.5±23.9) days. The gallbladder morphology was classified into four types (A, B, C and D) based on its size and shape on ultrasonography. The long diameter of the gallbladder gradually increased, with its shape gradually approaching normal. The proportions of gender, time of jaundice onset (calculated from birth), total bilirubin, direct bilirubin, γ-glutamyl transferase (γ-GT), gallbladder contraction rate, hepatic portal cyst, and cholangiography were compared among different types. The gallbladder length and width of type D were also compared with those of the healthy control group.Resluts:Among the 711 patients, 123(17.3%) were of type A, 330 (46.4%) were of type B, 112 (15.8%) were of type C, and 146 (20.5%) were of type D. There were no statistically significant differences in the male ratio, the timing of jaundice onset, total bilirubin levels, direct bilirubin levels, or γ-GT levels among the four types of patients (all P>0.05). However, the incidences of combined hepatic portal cysts in type C and D were higher than those in type A and B (all P<0.01). Notably, 68.5% (100/146) of type D patients had a gallbladder contraction rate of ≤25%, lower than the 91.8% (303/330) of type B and 95.5% (107/112) of type C ( χ2=42.41, 29.22, both P<0.001). The success rates of cholangiography for type C and D patients were 75.0% (84/112) and 76.7% (112/146), respectively, both higher than the 11.4% (14/123) for type A and 45.2% (149/330) for type B (all P<0.001). In the healthy control group, the length and width of gallbladder were larger than those in type D patients ( t=10.64, 11.62, both P<0.001). Conclusion:The ultrasonic gallbladder morphology in biliary atresia patients is diverse, and there are no significant clinical differences among the four types. However, there are differences in gallbladder contraction rates and the success rates of gallbladder imaging. The gallbladder length and width of type D patients, with a nearly normal gallbladder morphology, are smaller than those of healthy infants at the same age.

Objective To investigate the effects of different use methods of tourniquet on hidden blood loss and knee joint swelling in total knee arthroplasty(TKA),and to explore its potential benefits for postoperative rehabilitation.Methods A prospective study was conducted from March 2018 to March 2023 in Xuzhou Municipal Hospital Affiliated to Xuzhou Medical University,involving 131 patients who underwent TKA.The patients were divided into three groups based on the method of tourniquet use:44 patients routinely used a tourniquet in group A,48 patients only used a tourniquet during the application of bone cement in group B,and 39 patients did not use tourniquet in group C.Operation time,dressing changes,intraoperative blood loss,total blood loss,explicit blood loss,hidden blood loss,percentage of hidden blood loss,postoperative blood transfusion,hemoglobin(Hb),hematocrit(HCT),C-reactive protein(CRP),and creatine kinase(CK)were compared among groups.The pain and functional recovery were evaluated by visual analogue scale(VAS)and knee society clinical rating system(KSS)before surgery,and 3 days,1 month,and 3 months after surgery.The degree of limb swelling and the range of motion of the knee were also compared among groups.Results Group A had shorter operation time and less frequency of postoperative dressing changes than the other two groups(P<0.05).The hidden blood loss and total blood loss in group A were significantly less than those in group C(P<0.05),and the hidden blood loss and total blood loss volume in the three groups from low to high was group A