Objective To explore the impact of different moving patterns during the dip-coating process on thickness distributions of polymer heart valves.Methods Based on the volume of fluid(VOF)multiphase flow model,the Eulerian wall-film(EWF)model,and dynamic mesh technology,the dip-coating manufacturing process of polymer heart valves were numerically simulated.The effects of vertical,horizontal,and circular moving patterns on flow characteristics of the surface impregnation liquid and liquid film distributions under self-rotation conditions of the models were mainly studied.Subsequently,seven identical test points were set on each valve leaflet to collect thickness data,and the coefficient of variation(CV)was calculated to evaluate the uniformity of the liquid film thickness.Given that the vertical and horizontal patterns had fewer moving planes,limiting the optimization space,the circular pattern(45°)with richer moving planes was selected as the basis for optimization,and comparative analysis of numerical simulation was conducted.Results In the vertical pattern,the peak CV was 0.461 3;in the horizontal pattern,the CV was 0.060 8;and in the circular pattern,the CV at 30°,45° and 60° were 0.457 5,0.272 8,and 0.255 6,respectively.After optimization,the CV for the circular pattern(45°)decreased to 0.052 5,representing an 80.7％reduction compared to the pre-optimization value.Conclusions The moving patterns significantly affect the uniformity of dip-coating thickness distributions.The horizontal pattern demonstrates the best uniformity,while the vertical pattern shows the poorest uniformity.The CV for the circular pattern decreases as the angle increases,with its uniformity between that of the vertical and horizontal patterns.Optimization of moving pattern parameters based on simulation results has improved the uniformity of thickness distributions.

BACKGROUND:Post and core restoration is a common choice for tooth defects,but the repair effects of various post and core materials are different. OBJECTIVE:To evaluate the stress distribution at the post and core,tooth root,and bonding agent site of post and core models made of different elastic modulus post and core materials using finite element method. METHODS:A three-dimensional root canal treated maxillary central incisor model was built using three-dimensional modeling software,which was restored with a full ceramic crown.The post and core materials in the restoration used nanoceramic resin(elastic modulus=12.8 GPa),composite resin(elastic modulus=16 GPa),hybrid ceramic(elastic modulus=34.7 GPa),glass ceramic(elastic modulus=95 GPa),titanium alloy(elastic modulus=112 GPa),and zirconia(elastic modulus=209.3 GPa).The model was fixed in cortical bone.A 100 N concentrated force of 45° from the long axis of the tooth was applied to 1/3 of the crown and tongue side of the central incisor.The stress distribution of the post and core,dentin,and tooth-root bonding agent in the model was repaired by the maximum principal stress criterion. RESULTS AND CONCLUSION:(1)When the post and core materials with higher elastic modulus was used,the post-core stress in the repair model was more concentrated.When the elastic modulus of the post and core materials(nanoceramic resin and composite resin)was close to dentin,the stress distribution of the post and core was more uniform.The stress distribution of dentin in all restoration models was similar regardless of post and core materials.When the post and core with higher elastic modulus was used,more stress concentration was shown at the post and root bonding agent in the repair model.(2)The maximum stress values at the post and core,tooth root,and the bonding agent site of post and tooth root in the nanoceramic resin model were 31.00,33.21,and 0.51 MPa,respectively.The maximum stress values at the post and core,tooth root,and the bonding agent between the post and tooth root in the composite resin model were 36.84,33.14,and 0.59 MPa,respectively.In the mixed ceramic model,the maximum stress values at the post and core,tooth root,and the bonding agent between the post and tooth root were 64.05,32.83,and 1.00 MPa,respectively.In the glass ceramic model,the maximum stress values at the post and core,tooth root,and the bonding agent between the post and tooth root were 112.30,32.69,and 1.73 MPa,respectively.In the titanium alloy model,the maximum stress values of the post and core,tooth root,and the bonding agent between the post and tooth root were 120.00,32.17,and 1.86 MPa,respectively.In the zirconia model,the maximum stress values of the post and core,tooth root,and the bonding agent between the post and tooth root were 148.80,31.85,and 2.28 MPa,respectively.(3)The higher the elastic modulus of the post and core material,the higher the maximum stress at the post and core during restoration.The elastic modulus of the post and core material had no significant effect on the maximum stress of the dental bonding agent and dentin.

Objective To explore the impact of different moving patterns during the dip-coating process on thickness distributions of polymer heart valves.Methods Based on the volume of fluid(VOF)multiphase flow model,the Eulerian wall-film(EWF)model,and dynamic mesh technology,the dip-coating manufacturing process of polymer heart valves were numerically simulated.The effects of vertical,horizontal,and circular moving patterns on flow characteristics of the surface impregnation liquid and liquid film distributions under self-rotation conditions of the models were mainly studied.Subsequently,seven identical test points were set on each valve leaflet to collect thickness data,and the coefficient of variation(CV)was calculated to evaluate the uniformity of the liquid film thickness.Given that the vertical and horizontal patterns had fewer moving planes,limiting the optimization space,the circular pattern(45°)with richer moving planes was selected as the basis for optimization,and comparative analysis of numerical simulation was conducted.Results In the vertical pattern,the peak CV was 0.461 3;in the horizontal pattern,the CV was 0.060 8;and in the circular pattern,the CV at 30°,45° and 60° were 0.457 5,0.272 8,and 0.255 6,respectively.After optimization,the CV for the circular pattern(45°)decreased to 0.052 5,representing an 80.7％reduction compared to the pre-optimization value.Conclusions The moving patterns significantly affect the uniformity of dip-coating thickness distributions.The horizontal pattern demonstrates the best uniformity,while the vertical pattern shows the poorest uniformity.The CV for the circular pattern decreases as the angle increases,with its uniformity between that of the vertical and horizontal patterns.Optimization of moving pattern parameters based on simulation results has improved the uniformity of thickness distributions.

Objective:To identify and observe disease-causing gene variants and clinical phenotypes in a Han Chinese family with Leber congenital amaurosis (LCA).Methods:A retrospective study. A patient with LCA10 and his parents who had presented at Department of Ophthalmology of Henan Provincial People's Hospital on May 2022 were selected as the study subject. Detailed medical and family histories were recorded, fundus photography and flash electroretinogram (F-ERG) were performed. Peripheral venous blood samples (3 ml) of the proband and his parents were collected to extract whole genomic DNA, then whole exome sequencing (WES) and mitochondrial DNA (mtDNA) sequencing were carried out for the proband to determine the disease-causing gene and variants. All variants were annotated by bioinformatics analysis. According to the American College of Medical Genetics and Genomics (ACMG) guidelines, the pathogenicity of all detected variants were evaluated. Candidate variants were verified by Sanger sequencing, and in vitro minigene assay were performed to evaluate the impact of the missense variant with insufficient evidence on mRNA splicing.Results:The proband, male, 7-month-old, presented with an inability to follow light or objects, eye poking, photophobia, nystagmus, partial loss of retinal pigment epithelium around the fovea of the macula. At the age of 2 years old, F-ERG revealed severe reduction, elongation, or even no waveform of a-wave and b-wave in both eyes. No obvious abnormality was found in the clinical phenotype of his parents. The result of WES revealed that the proband carried two variants in exon 40 and exon 2 of CEP290, a frameshift variant c.5515_5518del (p.Glu1839Lysfs*11) (V1) and a novel missense variant c.74C>T (p.Ala25Val) (V2), respectively. The result of mitochondrial DNA sequencing was negative. Sanger sequencing confirmed that the heterozygous frameshift variant was inherited from his father and the heterozygous novel missense variant was inherited from his mother, which constituted compound heterozygous variants. In vitro minigene splicing assay confirmed that V2 created a new splicing donor at exon 2, leading to the in-frame deletion of 30bp fragment during transcription and loss of 10 amino acid residues in the protein. The two variants were pathogenic (V1) and likely pathogenic (V2) based on ACMG guidelines, respectively. Conclusions:The c.5515_5518del and novel c.74C>T compound heterozygous variants of the CEP290 gene probably are the cause of LCA10 in this family, which lead to the production of a truncated protein and aberrant splicing of pre-mRNA, respectively. LCA is characterized by early onset, severe impairment of visual function, and a wide range of disease-causing variations.

As the robotic assisted single port surgery arousing attention, a novel single-arm single-port micro-traumatic laparoscopic robotic surgical system is proposed in this study. From the perspective of the mechanics, joints with high rigidity and high reliability were utilized to realize the remote center of motion (RCM). Besides, the cost of consumables was reduced by adding the support of the rigid endoscope. From the perspective of the algorithm, high-precision motion control method and feedback force protection mechanism were implemented. The effectiveness of the aforementioned characteristics were verified by five clinical experiments of cholecystectomy. The results showed that the system is able to reduce the amount of bleeding, accelerate the patient recovery, reduce the infection risk and shorten the learning period. The robotic surgical system had significant clinical application value.
Humans ; Robotic Surgical Procedures ; Reproducibility of Results ; Laparoscopy ; Motion

Objective To compare the Roussouly classification of old thoracolumbar fractures combined with post-traumatic kyphosis with that of normal adults, evaluate the effect of different kyphosis angles on sagittal curvature of the thoracolumbar spine so as to provide a theoretical basis for the clinical status and clinical treatment plan of old thoracolumbar fractures combined with post-traumatic kyphosis.Methods A retrospective case control study was made on 49 cases of old thoracolumbar fractures with post-traumatic kyphosis treated from January 2014 to December 2015 (fracture group).Damaged segments of the spine were T11 in four cases, T12 in 14, L1 in 25 and L2 in six.Another 52 normal adult volunteers were chosen as controls.Whole spine X-ray film of the two groups was taken, and the difference in Roussouly classification of the sagittal spine curvature was compared between the two groups.Patients in fracture group were separated into subgroups depending on the Cobb angle (0°-10°, 10°-20°, 20°-30°, 30°-40°, respectively), and the difference in Roussouly classification was compared among subgroups.Results Roussouly classification in control group was five cases of type 1, 12 tpye 2, 25 type 3 and 10 type 4.Results in fracture group was 14 cases of type 1, 11 type 2, eight type 3 and 16 type 4.There were significant differences in Roussouly types between the two groups (P<0.05).According to Roussouly classification, there were two cases of types 1 and 2 and seven cases of types 3 and 4 in subgroup of Cobb angle between 0°-10°;four cases of types 1 and 2 and 10 cases of types 3 and 4 in subgroup of Cobb angle between 10°-20°;12 cases of types 1 and 2 and four cases of types 3 and 4 in subgroup of Cobb angle between 20°-30°;seven cases of types 1 and 2 and three cases of types 3 and 4 in subgroup of Cobb angle between 30°-40°.There were significant differences in Roussouly types among subgroups (P<0.05).Further, Roussouly types 1 and 2 were significantly increased when the Cobb angle was >20° (P<0.05).Conclusions Post-traumatic kyphosis in old thoracolumbar fractures affects spine sagittal curvature.Patients with sagittal spinal imbalance (Roussouly types 1 and 2) are more with increased Cobb angle.Moreover, Cobb angle >20°may be the reference basis for clinical intervention.