1.Preliminary study on the biological characteristics of heat shock cognate protein 20 of Schistosoma japonicum
Xingang YU ; Kaijian YUAN ; Yilong LI ; Xuanru MU ; Hui XU ; Qiaoyu LI ; Wenjing ZENG ; Zhiqiang FU ; Yang HONG
Chinese Journal of Schistosomiasis Control 2025;37(3):294-303
		                        		
		                        			
		                        			 Objective To clone and express the heat shock cognate protein 20 (SjHsc20) of Schistosoma japonicum, and to preliminarily investigate its biological characteristics. Methods The target fragment of the SjHsc20 gene was amplified using PCR assay and cloned into the pET-28a(+) expression plasmid to generate the recombinant expression vector pET-28a(+)-SjH-sc20, which was then transformed into Escherichia coli BL21 (DE3) competent cells. The recombinant SjHsc20 (rSjHsc20) protein was induced with isopropyl β-D-thiogalactopyranoside (IPTG) and purified, and the expression of the rSjHsc20 protein was checked with sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The immunogenicity of the rSjHsc20 protein was detected using Western blotting, and the transcriptional levels of SjHsc20 were quantified in S. japonicum worms at different developmental stages and in male and female adult worms using real-time quantitative PCR (RT-qPCR) assay. Thirty female BALB/c mice at ages 6 to 8 weeks were divided into three groups, including the rSjHsc20 immunization group, the PBS control group, and the ISA 206 adjuvant group, of 10 mice in each group. Mice in the rSjHsc20 immunization group were subcutaneously immunized with 20 μg rSjHsc20 on days 1, 15 and 31, and animals in the PBS control group were subcutaneously injected with the same volume of PBS on days 1, 15 and 31, while mice in the ISA 206 adjuvant group were subcutaneously immunized with the same volume of ISA 206 adjuvant on days 1, 15 and 31, respectively. All mice in each group were infected with (40 ± 2) S. japonicum cercariae via the abdomen 14 day following the last immunization. Levels of serum specific IgG and its subtypes IgG1 and IgG2 antibodies against rSjHsc20, and the serum titers of anti-rSjHsc20 antibody were detected in mice using indirect enzyme-linked immunosorbent assay (ELISA). All mice were sacrifice 42 days post-infection, and S. japonicum worms were collected from the hepatic portal vein and counted. The eggs per gram (EPG), worm burden reductions and egg burden reductions were estimated to evaluate the protective efficacy of the rSjHsc20 protein. Results The SjHsc20 gene had an open reading frame (ORF) with 756 bp in length and encoded 252 amino acids, and the rSjHsc20 protein had a relative molecular mass of approximately 29 kDa. The rSjHsc20 protein was recognized by the serum of mice infected with S. japonicum and the serum of mice immunized with the rSjHsc20 protein, indicating that rSjHsc20 had a good immunogenicity. There was a significant difference in the transcriptional levels of the SjHsc20 gene among the 7-day (1.001 4 ± 0.065 7), 12-day (2.268 3 ± 0.129 2), 21-day (1.378 5 ± 0.160 4), 28-day (1.196 4 ± 0.244 0), 35-day (1.646 3 ± 0.226 1), 42-day worms of S. japonicum (1.758 0 ± 0.611 1) (F = 38.45, P < 0.000 1), and the transcriptional level of the SjHsc20 gene was higher in the 12-day worms than in worms at other developmental stages (all P values < 0.000 1). The serum levels of anti-rSjHsc20 IgG antibody were 0.106 6 ± 0.010 7, 0.108 3 ± 0.010 4, and 0.553 2 ± 0.069 1 in the PBS control group, ISA 206 adjuvant group, and rSjHsc20 immunization group following the last immunization, respectively, and the serum levels of IgG1 antibody were 0.137 3 ± 0.054 0, 0.181 1 ± 0.096 8, and 1.765 8 ± 0.221 1, while the levels of IgG2a antibody were 0.280 3 ± 0.197 6, 0.274 0 ± 0.146 3, and 1.560 4 ± 0.106 0, respectively. There were significant differences in the serum levels of anti-rSjHsc20 IgG (F = 397.70, P < 0.000 1), IgG1 (F = 401.00, P < 0.000 1) and IgG2a antibodies (F = 229.70, P < 0.000 1) among the three groups, and the serum levels of anti-rSjHsc20 IgG, IgG1 and IgG2a antibodies were higher in the rSjHsc20 immunization group than in the PBS control group and the ISA 206 adjuvant group (all P values < 0.000 1). There was a significant difference in the IgG1/IgG2a ratio among the rSjHsc20 immunization group (1.177 2 ± 0.143 6), the PBS control group (0.428 4 ± 0.199 8) and the ISA 206 adjuvant group (0.559 9 ± 0.181 1) (F = 43.97, P < 0.000 1), and the IgG1/IgG2a ratio was > 1 in the rSjHsc20 immunization group, which was higher than in the PBS control group and the ISA 206 adjuvant group (both P values < 0.000 1). The titers of serum anti-rSjHsc20 antibody were all above 1∶16 384 in the rSjHsc20 immunization group following immunizations on days 1, 15 and 31, indicating that the rSjHsc20 protein had a strong immunogenicity. The mean worm burdens were (16.60±5.75), (15.80±5.58) worms per mouse and (14.40±5.75) worms per mouse in the PBS control group, the ISA 206 adjuvant group and the rSjHsc20 immunization group 42 days post-infection with S. japonicum cercariae (F = 0.50, P > 0.05), and the EPG were 68 370 ± 22 690, 67 972 ± 19 502, and 41 075 ± 13 251 in the PBS control group, the ISA 206 adjuvant group and the rSjHsc20 immunization group (F = 4.55, P < 0.05), with lower EPG in the PBS control group and the ISA 206 adjuvant group than in the rSjHsc20 immunization group (both P values < 0.05). Immunization with the rSjHsc20 protein resulted in a worm burden reduction of 13.25% and an egg burden reduction of 39.92% relative to the PBS control group. Conclusions SjHsc20 is successfully cloned and expressed, and the rSjHsc20 protein induces partial immunoprotective effects in mice, which provides a basis for deciphering the biological functions of SjHsc20 and assessing the potential of SjH-sc20 as a vaccine candidate. 
		                        		
		                        		
		                        		
		                        	
2.Advances of quadratus lumborum block in postoperative analgesia after hip joint surgery
Xinrui YIN ; Qiaoyu HAN ; Yaru LI ; Lu WANG ; Yi FENG ; Luyang JIANG
The Journal of Clinical Anesthesiology 2024;40(6):644-647
		                        		
		                        			
		                        			Hip surgery is often associated with moderate to severe postoperative pain due to exten-sive invasion.A safe and effective postoperative pain treatment can promote patients'recovering activities and facilitate the early functional recovery of the hip after the surgery.Although the routinely used intrave-nous self-controlled analgesia has an exquisite analgesic effect,it carries the risks of postoperative nausea and emesis,excessive sedation,intestinal paralysis,and even respiratory depression.As an alternative to transversus abdominis plane block(TAPB),lumbar quadratus block(QLB)has been gradually applied to the hip joint surgery.In this paper,we review the anatomical basis and characteristics of QLB and its clini-cal application in hip surgery,in order to provide the postoperative analgesia application of QLB.
		                        		
		                        		
		                        		
		                        	
3.The significance of vestibular function combined with videonystagmography in the clinical diagnosis of primary benign paroxysmal positional vertigo
Chinese Archives of Otolaryngology-Head and Neck Surgery 2024;31(10):639-641
		                        		
		                        			
		                        			OBJECTIVE To explore the clinical significance of vestibular function combined with videonystagmography in the diagnosis of primary benign paroxysmal positional vertigo.METHODS The detection rate of patients with primary benign paroxysmal positional vertigo(BPPV)was compared between naked eye examination and videonystagmography,and the abnormal vestibular function of patients with BPPV was detected by cold and hot test.RESULTS The total detection rates of primary benign paroxysmal positional vertigo by videonystagmography and naked eye examination were 91.18%and 67.65%,respectively.There was a significant difference between the two methods(χ2=17.270,P=0.000).There was significant difference between the nystagmus view and naked eye examination in the patients with benign paroxysmal positional vertigo of anterior and horizontal semicircular canal types(χ2=4.457,11.942,P<0.05).There was no significant difference in the abnormal number of gaze test,saccade test and stationary tracking test among different types of BPPV patients(P>0.05).Cold and heat tests showed that 68 patients(66.67%)with abnormal BPPV and 34(33.33%)with normal BPPV.CONCLUSION Vestibular function combined with nystagmus has certain clinical value in the diagnosis of primary benign paroxysmal positional vertigo.
		                        		
		                        		
		                        		
		                        	
4.Repair of soft tissue defect of the middle and lower leg with island flap
Chinese Journal of Medical Aesthetics and Cosmetology 2023;29(4):304-307
		                        		
		                        			
		                        			Objective:To investigate the methods and effect of wound repair after partial skin and soft tissue necrosis of middle and lower leg fracture surgery.Methods:Three kinds of island flaps were used to repair the wound after skin and soft tissue necrosis of middle and lower leg fracture surgery in 22 patients. Nine patients were repaired with sural neurotrophic fascial flaps, 7 patients with posterior tibial artery perforator flaps, and 6 patients with peroneal artery perforator flaps. The area of wound defect was 3.0 cm×3.8 cm to 12.0 cm×9.0 cm. The donor area was directly sutured, or free skin grafted.Results:All patients were the cases after partial skin and soft tissue necrosis of middle and lower leg fracture surgery, with bone, internal fixation plate or tendon exposed. The skin flaps in 21 patients were survived, and the wound healed by first intention. The sural neurotrophic fascial flap necrosis in one patient was due to hematoma and entrapment in vascular pedicle. After 5 to 24 months (mean 9 months) follow-up, texture of flaps was good, no ulcer occured, and outlook of the repaired wound was satisfied. The sutured wound of donor site and skin-grafting had healed by first stage intention.Conclusions:Repair with island flap is an ideal way to the defect wound after skin and soft tissue necrosis of middle and lower leg fracture surgery.
		                        		
		                        		
		                        		
		                        	
5.Silicate Ions Derived from Calcium Silicate Extract Decelerate Ang II-Induced Cardiac Remodeling
Xin LI ; Yanxin ZHANG ; Qishu JIN ; Qiaoyu SONG ; Chen FAN ; Yiren JIAO ; Chen YANG ; Jiang CHANG ; Zhihong DONG ; Yumei QUE
Tissue Engineering and Regenerative Medicine 2023;20(5):671-681
		                        		
		                        			 BACKGROUND:
		                        			Pathological cardiac hypertrophy is one of the main activators of heart failure. Currently, no drug can completely reverse or inhibit the development of pathological cardiac hypertrophy. To this end, we proposed a silicate ion therapy based on extract derived from calcium silicate (CS) bioceramics for the treatment of angiotensin II (Ang II) induced cardiac hypertrophy. 
		                        		
		                        			METHODS:
		                        			In this study, the Ang II induced cardiac hypertrophy mouse model was established, and the silicate ion extract was injected to mice intravenously. The cardiac function was evaluated by using a high-resolution Vevo 3100 small animal ultrasound imaging system. Wheat germ Agglutinin, Fluo4-AM staining and immunofluorescent staining was conducted to assess the cardiac hypertrophy, intracellular calcium and angiogenesis of heart tissue, respectively. 
		                        		
		                        			RESULTS:
		                        			The in vitro results showed that silicate ions could inhibit the cell size of cardiomyocytes, reduce cardiac hypertrophic gene expression, including atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP) and b-myosin heavy chain (b-MHC), decrease the content of intracellular calcium induced by Ang II. In vivo experiments in mice confirmed that intravenous injection of silicate ions could remarkably inhibit the cardiac hypertrophy and promote the formation of capillaries, further alleviating Ang II-induced cardiac function disorder. 
		                        		
		                        			CONCLUSION
		                        			This study demonstrated that the released silicate ions from CS possessed potential value as a novel therapeutic strategy of pathological cardiac hypertrophy, which provided a new insight for clinical trials. 
		                        		
		                        		
		                        		
		                        	
6.Effect of intensive blood pressure control after successful endovascular therapy on outcomes in patients with anterior circulation stroke: a multicentre, open-label, blinded-endpoint, randomized controlled trial
Chengfang LIU ; Qiwen DENG ; Hongchao SHI ; Feng ZHOU ; Yukai LIU ; Meng WANG ; Qiaoyu ZHANG ; Bingqi ZHANG ; Min LI ; Lei PING ; Tao WANG ; Haicun SHI ; Wei WANG ; Jiankang HOU ; Shi HUANG ; Jinfeng LYU ; Rui SHEN ; Yingdong ZHANG ; Junshan ZHOU
International Journal of Cerebrovascular Diseases 2023;31(6):401-408
		                        		
		                        			
		                        			Objective:To compare the effects of intensive and standard blood pressure control on the outcomes of patients with acute ischemic stroke in the anterior circulation who have successfully recanalized after endovascular therapy (EVT).Methods:A multicenter, open-label, blinded-endpoint, randomized controlled design was used. Patients with anterior circulation stroke received EVT and successfully recanalized in Nanjing First Hospital, Nanjing Medical University and several branch hospitals from July 2020 to October 2022 were prospectively included. They were randomly divided into the intensive blood pressure control group (target systolic blood pressure [SBP] 100-120 mmHg) or the standard blood pressure control group (target SBP 121-140 mmHg). The blood pressure of both groups needs to achieve the target within 1 h and maintain for 72 h. The primary outcome endpoint was outcome at 90 d, and the good outcome was defined as a score of 0-2 on the modified Rankin Scale. Secondary outcome endpoints included early neurological improvement, symptomatic intracranial hemorrhage (sICH) within 24 h, and death and serious adverse events within 90 d.Results:A total of 120 patients were included, including 63 in the intensive blood pressure control group and 57 in the standard blood pressure control group. There was no statistically significant difference in baseline characteristics between the two groups. The SBP at 72 h after procedure was 122.7±8.1 mmHg in the intensive blood pressure control group and 130.2±7.4 mmHg in the standard blood pressure control group, respectively. There were no significantly differences in the good outcome rate (54.0% vs. 54.4%; χ2=0.002, P=0.963), the early neurological improvement rate (45.2% vs. 34.5%; χ2=1.367, P=0.242), the incidence of sICH (6.3% vs. 3.5%; P=0.682), mortality (7.9% vs. 14.0%; χ2=1.152, P=0.283) and the incidence of serious adverse events (12.7% vs. 15.8%; χ2=0.235, P=0.628) at 90 d between the intensive blood pressure control group and the standard blood pressure control group. Conclusion:In patients with anterior circulation stroke and successful revascularization of EVT, early intensive blood pressure control don’t improve clinical outcomes and reduce the incidence of sICH.
		                        		
		                        		
		                        		
		                        	
7.Clinical value of split domino donor auxiliary liver transplantation
Wenjie ZHANG ; Qingxiang XU ; Guoqiang LI ; Decai YU ; Yang YUE ; Xinhua ZHU ; Qiaoyu LIU ; Heng CUI ; Beicheng SUN
Chinese Journal of Digestive Surgery 2022;21(2):287-294
		                        		
		                        			
		                        			Objective:To investigate the clinical value of split domino donor auxiliary liver transplantation.Methods:The retrospective and descriptive study was conducted. The clinco-pathological data of 3 liver transplantation recipients who were admitted to Nanjing Drum Tower Hospital affiliated to Nanjing University Medical School and 1 liver transplantation recipient who was admitted to external hospital in September 2018 were collected. The first case was male, aged 22 years, who was diagnosed as type II citrullinemia (CTLN2). The second case undergoing liver transplantation in external hospital was male, aged 59 years, who was diagnosed as decompensated alcoholic cirrhosis. The third case was female, aged 52 years, who was diagnosed as hepatocellular carcinoma of right lobe of liver. The fourth case was female, aged 51 years, who was diagnosed as hepatocellular carcinoma of right lobe of liver. The donor liver from a brain and cardiac death donor was split in vitro into the left liver and the right liver, in which the right liver without middle hepatic vein, and the modified piggyback liver transplantation using the left liver and the classical orthotropic liver transplantation using the right liver was conducted on the first and the second case, respectively. The original liver of the first case was split in vivo into the left liver and the right liver, and the piggyback auxiliary liver transplantation using the left liver and the piggyback auxiliary liver transplantation using the right liver was conducted on the third and the fourth case who underwent extended right hemihepatectomy, respectively. Observation indicators: (1) intraoperative situations; (2) follow-up. Follow-up was conducted using outpatient examination and telephone interview to detect liver function, liver imaging, complication and survival of recipients up to October 2021.Results:(1) Intraoperative situations. Liver transplantation was conducted successfully on the first, third and fourth case, with the operation time, the volume of intraoperative blood loss, the donor liver cold ischemia time, the graft-to-recipient weight ratio were 400 minutes, 370 minutes, 390 minutes, 600 mL, 1 300 mL, 1 600 mL, 230 minutes, 152 minutes, 135 minutes, 1.2%, 0.8%, 1.1%. (2) Follow-up. B-ultrasound examination of the first, third and fourth case after liver transplantation showed that the blood flow was normal, and all the 3 cases discharged and were followed up at postoperative 1, 6 and 12 month. The liver function, the level of blood ammonia and citrulline were normal of the first, third and fourth case at postoperative 1 week. Imaging examina-tion showed normal liver morphology of the first and third case, and a transplanted liver atrophy caused by portal vein steal of the fourth case. ① The level of alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TBil), direct bilirubin (DBil) of the first case before liver transplantation, at postoperative 1 day, 2 day, 3 day, 7 day, 10 day, 6 month and 1 year were 22.8 U/L, 404.1 U/L, 355.5 U/L, 289.6 U/L, 31.0 U/L, 23.1 U/L, 42.1 U/L and 25.8 U/L, 31.5 U/L, 517.7 U/L, 327.6 U/L, 172.9 U/L, 15.9 U/L, 21.4 U/L, 47.5 U/L and 29.7 U/L, 3.8 μmol/L, 92.1 μmol/L, 87.4 μmol/L, 79.7 μmol/L, 90.1 μmol/L, 130.6 μmol/L, 33.8 μmol/L and 25.4 μmol/L, 2.3 μmol/L, 47.0 μmol/L, 44.1 μmol/L, 47.1 μmol/L, 57.4 μmol/L, 70.9 μmol/L, 24.7 μmol/L and 9.7 μmol/L, respectively. The level of citrulline and blood ammonia of the first case before and after liver transplantation were 999.0 μmol/L, 196.0 μmol/L and 14.6 μmol/L, 9.0 μmol/L, respectively. The first case was followed up for 3 years and survived without any liver transplantation related complication. ② The level of ALT, AST, TBil, DBil of the third case before liver transplantation, at postoperative 1 day, 2 day, 3 day, 7 day, 10 day, 6 month and 1 year were 21.3 U/L, 143.9 U/L, 182.0 U/L, 132.0 U/L, 17.2 U/L, 10.1 U/L, 17.6 U/L and 16.8 U/L,20.0 U/L, 291.0 U/L, 227.5 U/L, 106.4 U/L, 15.8 U/L, 10.8 U/L, 17.1 U/L and 19.4 U/L, 6.8 μmol/L, 50.9 μmol/L, 45.0 μmol/L, 34.0 μmol/L, 32.4 μmol/L, 22.3 μmol/L, 12.8 μmol/L and 14.9 μmol/L, 2.5 μmol/L, 18.4 μmol/L, 17.2 μmol/L, 14.9 μmol/L, 14.8 μmol/L, 12.1 μmol/L, 3.6 μmol/L and 4.4 μmol/L. The level of citrulline and blood ammonia of the third case after liver transplantation were 24.9 μmol/L and 16.0 μmol/L. The third case was followed up for 3 years and survived without any liver transplantation related complication. ③ The level of ALT, AST, TBil, DBil of the fourth case before liver transplantation, at postoperative 1 day, 2 day, 3 day, 7 day, 10 day, 6 month and 1 year were 35.0 U/L, 268.7 U/L, 682.0 U/L, 425.8 U/L, 57.5 U/L, 34.0 U/L, 29.4 U/L and 18.1 U/L, 37.0 U/L, 419.1 U/L, 436.2 U/L, 139.5 U/L, 35.2 U/L, 32.4 U/L, 54.7 U/L and 32.8 U/L, 7.1 μmol/L, 64.2 μmol/L, 41.4 μmol/L, 17.6 μmol/L, 34.2 μmol/L, 48.7 μmol/L, 14.1 μmol/L and 21.8 μmol/L, 2.8 μmol/L, 18.9 μmol/L, 16.1 μmol/L, 6.0 μmol/L, 14.6 μmol/L, 26.7 μmol/L, 3.9 μmol/L, 11.8 μmol/L. The level of citrulline and blood ammonia of the fourth case after liver transplantation were 8.4 μmol/L and 47.0 μmol/L. One week after surgery, the transplanted right liver of the fourth case occurred atrophy due to blood stealing from the right branch of the portal vein. B-ultrasound examination showed that the reflux of the hepatic artery and hepatic vein was unobstructed. Immunosuppressants were discontinued 3 months after operation on the fourth case and there was no complication such as rejection, bile leakage, biliary stricture, thrombosis and vascular stricture during follow-up. The fourth case died of lung metastasis 19 months after operation.Conclusion:Split domino donor auxiliary liver transplantation can be used for the treatment of metabolic liver disease and advanced hepatocellular carcinoma.
		                        		
		                        		
		                        		
		                        	
8.Comparison of hyoid bone positions among patients with different sagittal skeletal malocclusions
YAN Zhebin ; XIAO Chuqiao ; LI Yaqi ; CHENG Qiaoyu ; FAN Peidi ; WANG Jun ; XIONG Xin
Journal of Prevention and Treatment for Stomatological Diseases 2022;30(11):798-804
		                        		
		                        			Objective:
		                        			 To compare the hyoid bone position among patients with different sagittal skeletal malocclusions to provide a reference for clinicians to formulate treatment plans.
		                        		
		                        			Methods:
		                        			Lateral cephalograms of 284 orthodontic patients were selected. According to ANB angles, the types of skeletal malocclusion of patients were determined as follows: Class Ⅰ (1° ≤ ANB ≤ 5°), Class Ⅱ (ANB>5°) and Class Ⅲ (ANB<1°). Ten parameters were used to determine hyoid positions. After comparing the hyoid positions of the three groups, stratified analyses based on sex and age were conducted. 
		                        		
		                        			Results :
		                        			 No significant differences in demographic and vertical facial type features among skeletal Classes Ⅰ, Ⅱ and Ⅲ patients were observed (P>0.05). The angle between the Gonion-hyoid point line and the hyoid point-Menton line (Go-Hy-Me) of Class Ⅱ patients was significantly smaller than that of Class Ⅰ patients, and the angle between the most anterior and inferior point of the third cervical vertebra-hyoid point line and the hyoid point-Sella line (C3-Hy-S) of Class Ⅲ patients was smaller than that of Class I patients (P<0.05). Age-stratified analysis showed that in the juvenile group, the C3-Hy-S of Class Ⅲ patients was significantly smaller than that of Class Ⅰ patients in males and females (P<0.05). In the adult female group, the Go-Hy-Me of Class Ⅱ patients was significantly smaller, and the distance from the hyoid point to the mandibular plane (Hy-MP) was larger than that noted in Class Ⅰ patients (P<0.05); no significant difference in hyoid position between male Class Ⅱ and I patients was observed (P>0.05).
		                        		
		                        			Conclusions
		                        			Compared with Class Ⅰ patients, the hyoid bone of Class Ⅱ patients in adult females was farther away from the mandible and that of Class Ⅲ patients in juveniles was farther away from the cervical vertebra and posterior cranial base.
		                        		
		                        		
		                        		
		                        	
9.Relation of thrombus composition with stroke etiology and influence of thrombus composition in prognoses of stroke
ZhaoJun MEI ; Wei CHEN ; Yu QIAN ; Enxi XU ; Kan CAO ; Peisong LU ; Qiaoyu LI ; Xinyu LU
Chinese Journal of Neuromedicine 2021;20(1):35-39
		                        		
		                        			
		                        			Objective:The composition of thrombi obtained during mechanical thrombectomy in patients with acute ischemic stroke is analyzed to investigate its relation with stroke etiology and its influence in surgical parameters and clinical prognoses.Methods:The thrombi and clinical data of 41 patients with acute ischemic stroke directly treated by mechanical thrombectomy in our hospital from January 2019 to December 2019 were collected. Hematoxylin-eosin (HE) staining was used to quantitatively analyze the composition of thrombi, and the components of thrombi in patients with different causes of stroke (large artery atherosclerosis [LAA], cardiogenic embolism [CE], and unexplained type) were compared. These patients were divided into erythrocyte-rich group (erythrocyte content>fibrin content) and fibrin-rich group (erythrocyte content
		                        		
		                        	
10.Finite element analysis of determining corneal biomechanical properties in vivo based on Corvis ST.
Qiaoyu MENG ; Xiaojun WANG ; Weiyi CHEN ; Xiaona LI ; Rui HE
Journal of Biomedical Engineering 2020;37(4):608-613
		                        		
		                        			
		                        			The decrease of corneal stiffness is the key factor leading to keratoconus, and the corneal collagen fiber stiffness and fiber dispersion are closely related to the corneal biomechanical properties. In this paper, a finite element model of human cornea based on corneal microstructure, namely collagen fiber, was established before and after laser assisted in situ keratomileusis (LASIK). By simulating the Corvis ST process and comparing with the actual clinical results, the hyperelastic constitutive parameters and corneal collagen fiber stiffness modulus of the corneal material were determined before and after refractive surgery. After LASIK, the corneal collagen fiber stiffness modulus increased significantly, and was highly correlated with central corneal thickness (CCT). The predictive relationship between the corneal collagen fiber stiffness modulus and the corresponding CCT before and after surgery was: = exp(9.14 - 0.009CCT ), = exp(8.82 - 0.008CCT ). According to the results of this study, the central corneal thickness of the patient can be used to estimate the preoperative and postoperative collagen fiber stiffness modulus, and then a personalized corneal model that is more consistent with the actual situation of the patient can be established, providing a theoretical reference for more accurately predicting the safe surgical cutting amount of the cornea.
		                        		
		                        		
		                        		
		                        			Biomechanical Phenomena
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		                        			Cornea
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		                        			Corneal Topography
		                        			;
		                        		
		                        			Finite Element Analysis
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		                        			Humans
		                        			;
		                        		
		                        			Keratomileusis, Laser In Situ
		                        			;
		                        		
		                        			Myopia
		                        			
		                        		
		                        	
            

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