Objective To prepare virus-like particles (VLPs) for yellow fever virus (YFV) using the pACYCDuet-1 single-plasmid dual expression system. Methods Gene fragments including NS1, NS5, and 5' untranslated region (UTR) and 3' UTR fragment of YFV were cloned into the expression plasmid pACYCDuet-1-MS2-TMpac (carrying MS2 coat protein gene) and transformed into E. coli BL21(DE3) for expression. VLPs were observed by TEM. After DNase I/RNase A digestion, RNA was extracted and transcribed into cDNA, which was subjected to fluorescence quantitative PCR detection. Results According to SN/T 3560-2013, double digestion and colony PCR of pACYCDuet-1-MS2-TMpac-YFV both produced expected bands. SDS-PAGE showed a target band at 25-35 kDa. RT-PCR amplified VLPs after enzyme digestion, and TEM revealed VLPs with clear edges and translucent interiors. Thus, the plasmid was successfully constructed, and the phage coat protein packaged YFV genes with nuclease resistance. Conclusion VLPs containing specific gene fragments of yellow fever virus have been successfully prepared. These nuclease-resistant VLPs can serve as safe and stable quality control materials to ensure the reliability of laboratory detection for YFV.

BACKGROUND:The asymmetrical biomechanical environment of adolescent idiopathic scoliosis can lead to further wedge deformation of the vertebral body,which may affect cardiopulmonary function and compress nerves in severe cases.Adolescent idiopathic scoliosis with different degrees of scoliosis should be treated with exercise,bracing,and surgery.However,the mechanical mechanism of selecting an orthopedic approach remains unclear due to the individual variability of patients.OBJECTIVE:To investigate the biomechanical mechanism of different orthopedic modalities for the treatment of adolescent idiopathic scoliosis to provide a basis for clinical selection of treatment modalities based on the spine model of adolescent idiopathic scoliosis patients.METHODS:Based on the CT images of an adolescent idiopathic scoliosis patient,a scoliosis model(C7-L5)was reconstructed in Mimics software in three dimensions,and lateral thrust force was applied at the T8/T9 thorax and vertical distraction force was applied over the C7 vertebra with the magnitude of 20,40,60,80,100,and 120 N.The intervertebral disc stress and vertebral displacement in concave and convex sides,and Cobb angle of the spine were analyzed under two orthopedic modalities.RESULTS AND CONCLUSION:(1)With lateral thrust,there was no significant change in the C7T1-T7T8 intervertebral disc.The concave and convex stress of T7T8-L4L5 segment decreased first and then increased with the increase of lateral thrust force.The correction effect of lateral thrust on the segment near T8T9 was obvious and weakened with the extension of the segment to the cephalic and caudal ends.At 120 N of lateral thrust,the thoracic Cobb angle changed from 53.2° to 32.5° and the lumbar Cobb angle changed from 50.2° to 43.9°.(2)With the vertical distraction,the thoracic intervertebral disc stresses first decreased and then increased,and all the lumbar disc stresses decreased.The C7 displacement was the most obvious,and the correction effect gradually diminished with the segment extended to the caudal end.At a vertical distraction force of 120 N,the thoracic Cobb angle changed from 53.2° to 39.4° and the lumbar Cobb angle changed from 50.2° to 47.6°.(3)It is concluded that both orthopedic modalities provide improvement in the degree of scoliosis,with the thoracic correction being greater than the lumbar correction.Also,the asymmetric stress distribution on the concave and convex sides is improved,which contributes to normal bone growth.A vertical distraction approach is appropriate for larger Cobb angles,and a lateral thrust approach is appropriate for smaller Cobb angles.The results of this study help to understand the mechanism of spinal orthosis and provide a theoretical basis for the choice of orthopedic approach.

BACKGROUND:Adolescent lumbar disc herniation is the main cause of low back pain in adolescents. At present,most of them are treated by conservativetreatment. When long-term non-surgical treatment attempts,surgery may be necessary to prevent further injury when the patient's symptoms are notsufficiently relieved or when the patient has symptoms of single nerve paralysis or compression of the cauda equina,it is very important to choose a suitable interbody fusion device for the surgical treatment of the patients.OBJECTIVE:To explore the effects of minimally invasive interbody fusion with different heights on lumbar biomechanics in patients with adolescent lumbar disc herniation.METHODS:CT scans of a 17-year-old male patient with adolescent lumbar disc herniation (L4-5 segment herniation) were collected. After the three-dimensional reconstruction of MIMICS,the interbody fusion device equal to and 3 mm higher than the intervertebral space was selected for analysis,so two expandablemixed material interbody fusion devices were designed and reconstructed. Fusion device L:11 mm high front,9 mm high posterior,9 mm wide,28 mmlong,and fusion device H:14 mm high front,11 mm high posterior,11 mm wide,28 mm long and the lumbar fusion device was modeled. The fusion deviceand lumbar spine model were optimized,inversely modeled,and then imported into ABAQUS,and finally the 3D model of lumbar fusion was obtained.The physiological activities of the human body were simulated,such as lumbar extension,forward bending,right bending,and left bending,to obtain thecorresponding stress contours. The biomechanical characteristics of the L4-5 vertebra under seven different working conditions were observed.RESULTS AND CONCLUSION:(1) The maximum stress of the two kinds of fuses was in the condition of forward bending and backward extension,the stress value of H fuses was (18.27±3.80) Mpa and (15.02±3.24) Mpa;the stress value of L fuses was (9.16±0.05) Mpa and (9.17±1.83) Mpa. The stress values of the end plate of the H-fusion in the extension station were (19.11±4.03) Mpa and (16.32±3.72) Mpa respectively. The stress values of the L-fusion end plate were (9.13±0.01) Mpa and (4.92±1.01) Mpa respectively. (2) The stress of H-type fusing end plate was higher than that of L-type fusing end plate except for L-5 end plate at neutral position (P<0.05). (3) Choosing an interbody fusion device with a height of more than 3 mm in the same intervertebral space has a more stable biomechanics.

Objective A scoping review of studies on pulmonary prehabilitation in cardiac surgery patients was conducted to provide evidence support for the construction of a preoperative pulmonary rehabilitation program for cardiac surgery patients that suitable for China's national conditions.Methods In accordance with the scope review's research methodologies,databases including PubMed,Embase,Web of Science,CINAHL,CNKI and Wanfang were searched by the computer for relevant studies.The deadline for retrieval is from the establishment of databases to June,2024.The included literature was systematically analyzed.Results 26 articles were finally included.Among them,4 were quasi-experiment studies,while the other 22 were randomized controlled trials.Forms of the intervention included comprehensive breathing exercises,inspiratory muscle training,positive expiratory pressure,incentive spirometer training and balloon blowing training.The intervention initiation ranged from 10 weeks to 1 day preoperatively;the outcome measures included postoperative pulmonary complications,lung function metrics,the 6-Minute Walk Test,duration of mechanical ventilation,length of hospital stay,patient-reported outcomes and so on.Conclusion There remains a deficiency in standardized protocols for preoperative pulmonary rehabilitation training among patients undergoing cardiac surgery.High-quality studies should be conducted,and intervention strategies for pulmonary prehabilitation in cardiac surgery patients should be optimized and a unified evaluation standard system should be established.

Objective To compare the value of standard deviation(SD)method and root mean square(RMS)method for measuring signal-to-noise ratio(SNR)of MRI of American College of Radiology(ACR)phantom based on phased array coils.Methods ACR phantom was scanned with head coil(Head),abdominal coil(Anterior),dual piece flexible coil(Flex L)and abdominal coil+flexible coil(Anterior+Flex L)each for 6 times,respectively,with sequences of axial T 1W-spin echo(SE)and T2W-SE.And the scanning schemes were divided into 8 groups based on 4 types of coils and 2 sequences.SNR of 8 groups were measured with standard deviation method and root mean square method,respectively,and the differences between the above 2 methods were observed.Results For T1W-SE sequence,SNRsD of MRI based on Head,Anterior,Flex L and Anterior+Flex L was 1.25±0.07,0.56±0.02,1.15±0.10 and 1.04±0.11,respectively,while SNRRMs was 1.10±0.07,0.58±0.03,1.01±0.13 and 1.31±0.15,respectively.For T2W-SE sequence,SNRsD was 1.40±0.08,0.48±0.02,1.04±0.07 and 1.08±0.06,respectively,while SNRRMs was 1.29±0.09,0.53±0.03,0.84±0.08 and 1.35±0.12,respectively.Compared pairwise,significant difference of SNRsD was found in 9 pairs(all P＜0.05),while of SNRRMs was detected in 10 pairs(all P＜0.05).Conclusion Compared with standard deviation method,root mean square method was more suitable for measuring SNR of MRI of ACR phantom based on phased array coils.

BACKGROUND:Adolescent lumbar disc herniation is the main cause of low back pain in adolescents. At present,most of them are treated by conservativetreatment. When long-term non-surgical treatment attempts,surgery may be necessary to prevent further injury when the patient's symptoms are notsufficiently relieved or when the patient has symptoms of single nerve paralysis or compression of the cauda equina,it is very important to choose a suitable interbody fusion device for the surgical treatment of the patients.OBJECTIVE:To explore the effects of minimally invasive interbody fusion with different heights on lumbar biomechanics in patients with adolescent lumbar disc herniation.METHODS:CT scans of a 17-year-old male patient with adolescent lumbar disc herniation (L4-5 segment herniation) were collected. After the three-dimensional reconstruction of MIMICS,the interbody fusion device equal to and 3 mm higher than the intervertebral space was selected for analysis,so two expandablemixed material interbody fusion devices were designed and reconstructed. Fusion device L:11 mm high front,9 mm high posterior,9 mm wide,28 mmlong,and fusion device H:14 mm high front,11 mm high posterior,11 mm wide,28 mm long and the lumbar fusion device was modeled. The fusion deviceand lumbar spine model were optimized,inversely modeled,and then imported into ABAQUS,and finally the 3D model of lumbar fusion was obtained.The physiological activities of the human body were simulated,such as lumbar extension,forward bending,right bending,and left bending,to obtain thecorresponding stress contours. The biomechanical characteristics of the L4-5 vertebra under seven different working conditions were observed.RESULTS AND CONCLUSION:(1) The maximum stress of the two kinds of fuses was in the condition of forward bending and backward extension,the stress value of H fuses was (18.27±3.80) Mpa and (15.02±3.24) Mpa;the stress value of L fuses was (9.16±0.05) Mpa and (9.17±1.83) Mpa. The stress values of the end plate of the H-fusion in the extension station were (19.11±4.03) Mpa and (16.32±3.72) Mpa respectively. The stress values of the L-fusion end plate were (9.13±0.01) Mpa and (4.92±1.01) Mpa respectively. (2) The stress of H-type fusing end plate was higher than that of L-type fusing end plate except for L-5 end plate at neutral position (P<0.05). (3) Choosing an interbody fusion device with a height of more than 3 mm in the same intervertebral space has a more stable biomechanics.

BACKGROUND:The asymmetrical biomechanical environment of adolescent idiopathic scoliosis can lead to further wedge deformation of the vertebral body,which may affect cardiopulmonary function and compress nerves in severe cases.Adolescent idiopathic scoliosis with different degrees of scoliosis should be treated with exercise,bracing,and surgery.However,the mechanical mechanism of selecting an orthopedic approach remains unclear due to the individual variability of patients.OBJECTIVE:To investigate the biomechanical mechanism of different orthopedic modalities for the treatment of adolescent idiopathic scoliosis to provide a basis for clinical selection of treatment modalities based on the spine model of adolescent idiopathic scoliosis patients.METHODS:Based on the CT images of an adolescent idiopathic scoliosis patient,a scoliosis model(C7-L5)was reconstructed in Mimics software in three dimensions,and lateral thrust force was applied at the T8/T9 thorax and vertical distraction force was applied over the C7 vertebra with the magnitude of 20,40,60,80,100,and 120 N.The intervertebral disc stress and vertebral displacement in concave and convex sides,and Cobb angle of the spine were analyzed under two orthopedic modalities.RESULTS AND CONCLUSION:(1)With lateral thrust,there was no significant change in the C7T1-T7T8 intervertebral disc.The concave and convex stress of T7T8-L4L5 segment decreased first and then increased with the increase of lateral thrust force.The correction effect of lateral thrust on the segment near T8T9 was obvious and weakened with the extension of the segment to the cephalic and caudal ends.At 120 N of lateral thrust,the thoracic Cobb angle changed from 53.2° to 32.5° and the lumbar Cobb angle changed from 50.2° to 43.9°.(2)With the vertical distraction,the thoracic intervertebral disc stresses first decreased and then increased,and all the lumbar disc stresses decreased.The C7 displacement was the most obvious,and the correction effect gradually diminished with the segment extended to the caudal end.At a vertical distraction force of 120 N,the thoracic Cobb angle changed from 53.2° to 39.4° and the lumbar Cobb angle changed from 50.2° to 47.6°.(3)It is concluded that both orthopedic modalities provide improvement in the degree of scoliosis,with the thoracic correction being greater than the lumbar correction.Also,the asymmetric stress distribution on the concave and convex sides is improved,which contributes to normal bone growth.A vertical distraction approach is appropriate for larger Cobb angles,and a lateral thrust approach is appropriate for smaller Cobb angles.The results of this study help to understand the mechanism of spinal orthosis and provide a theoretical basis for the choice of orthopedic approach.

Objective A scoping review of studies on pulmonary prehabilitation in cardiac surgery patients was conducted to provide evidence support for the construction of a preoperative pulmonary rehabilitation program for cardiac surgery patients that suitable for China's national conditions.Methods In accordance with the scope review's research methodologies,databases including PubMed,Embase,Web of Science,CINAHL,CNKI and Wanfang were searched by the computer for relevant studies.The deadline for retrieval is from the establishment of databases to June,2024.The included literature was systematically analyzed.Results 26 articles were finally included.Among them,4 were quasi-experiment studies,while the other 22 were randomized controlled trials.Forms of the intervention included comprehensive breathing exercises,inspiratory muscle training,positive expiratory pressure,incentive spirometer training and balloon blowing training.The intervention initiation ranged from 10 weeks to 1 day preoperatively;the outcome measures included postoperative pulmonary complications,lung function metrics,the 6-Minute Walk Test,duration of mechanical ventilation,length of hospital stay,patient-reported outcomes and so on.Conclusion There remains a deficiency in standardized protocols for preoperative pulmonary rehabilitation training among patients undergoing cardiac surgery.High-quality studies should be conducted,and intervention strategies for pulmonary prehabilitation in cardiac surgery patients should be optimized and a unified evaluation standard system should be established.

Objective To compare the value of standard deviation(SD)method and root mean square(RMS)method for measuring signal-to-noise ratio(SNR)of MRI of American College of Radiology(ACR)phantom based on phased array coils.Methods ACR phantom was scanned with head coil(Head),abdominal coil(Anterior),dual piece flexible coil(Flex L)and abdominal coil+flexible coil(Anterior+Flex L)each for 6 times,respectively,with sequences of axial T 1W-spin echo(SE)and T2W-SE.And the scanning schemes were divided into 8 groups based on 4 types of coils and 2 sequences.SNR of 8 groups were measured with standard deviation method and root mean square method,respectively,and the differences between the above 2 methods were observed.Results For T1W-SE sequence,SNRsD of MRI based on Head,Anterior,Flex L and Anterior+Flex L was 1.25±0.07,0.56±0.02,1.15±0.10 and 1.04±0.11,respectively,while SNRRMs was 1.10±0.07,0.58±0.03,1.01±0.13 and 1.31±0.15,respectively.For T2W-SE sequence,SNRsD was 1.40±0.08,0.48±0.02,1.04±0.07 and 1.08±0.06,respectively,while SNRRMs was 1.29±0.09,0.53±0.03,0.84±0.08 and 1.35±0.12,respectively.Compared pairwise,significant difference of SNRsD was found in 9 pairs(all P＜0.05),while of SNRRMs was detected in 10 pairs(all P＜0.05).Conclusion Compared with standard deviation method,root mean square method was more suitable for measuring SNR of MRI of ACR phantom based on phased array coils.

Objective:To evaluate the feasibility, safety and efficacy of a domestic novel endoscopic clip for the treatment of gastrointestinal perforation in an animal model, and discuss its potential clinical adoption.Methods:Eight experimental pigs were randomly assigned to either an experimental group receiving the domestic novel endoscopic clip or a control group receiving an over-the-scope clip system (OTSC) using the random number table. Each animal underwent the creation of 2 cm perforations in the stomach and rectum, which were immediately sealed with clips. The performance, safety, and immediate closure rate of the clips during surgery were evaluated. Endoscopic examinations were conducted on days 3, 7, 14, 21, and 35 post-surgery to assess clip retention and wound healing. At the end of the observation period, animals were euthanized to evaluate wound healing, and histological examinations of the wound sites were conducted.Results:Both groups, consisting of 4 pigs each, successfully created and closed artificial perforations in both the stomach and rectum without intraoperative adverse events in either group such as accidental activation, device failure, or malfunctions in the delivery system. Endoscopic clip performance in the stomach were uniformly rated as 3 in all 4 pigs in the control group, while in the experimental group, 3 pigs were scored as 3 and 1 as 2. For rectal clip performance, 3 pigs were scored as 3 in both groups. One pig were scored as 1 in the experimental group, and the remaining pig in the control group were 2. All pigs survived the observation period without any postoperative complications. One clip (in the control group, rectal site) naturally dislodged during the observation period, while the other clips remained in place. Gross pathological examination revealed that the gastric surgical sites in all 8 pigs and the rectal sites in 7 pigs had healed, with wound healing scores of 3. However, 1 pig (control group) exhibited poor healing of the rectal mucosal incision, with persistent redness and swelling, and a wound healing score of 2. Histopathological examination showed similar levels of inflammation, cell necrosis, and vascular proliferation between the two groups, without ulcer formation observed.Conclusion:The domestically produced novel endoscopic clip exhibits simplicity in operation and demonstrates comparable technical feasibility, safety, and efficacy to OTSC. Its promising clinical application warrants further investigation and promotion through additional clinical research.