BACKGROUND:The pelvis has abundant trabecular bone content,but the ability of conventional sacroiliac percutaneous fixation to control trabecular bone is limited,leading to fixation failure.Therefore,the development of devices that can more effectively control trabecular bone tension is of significant importance.OBJECTIVE:The mechanical properties of a novel sacroiliac tension screw were investigated using biomechanical testing and numerical modeling analysis,along with an assessment of the reliability of the pull-out force numerical model.METHODS:A mechanical model was established based on the working principle of the novel sacroiliac tension screw.Numerical methods were employed to analyze its pull-out performance,validated through mechanical testing with polyurethane material to assess the reliability of the pull-out force numerical model.Using pelvic specimens,the mechanical effectiveness of the novel sacroiliac tension screw in repairing sacroiliac joint injuries was analyzed under normal standing posture,along with an evaluation of the load stiffness of different pelvic models in the standing position.RESULTS AND CONCLUSION:(1)The average error between the computed values of the numerical model and the measured values was 13.19％,indicating a certain level of validity for the numerical model.(2)The damage to the polyurethane material after the extraction of the screw was less pronounced in the novel screw group.(3)The average effective holding displacement for the novel screw was approximately(9.24±0.27)mm,significantly greater than the average displacement of(1.71±0.57)mm observed with the lag screws.However,the maximum resistance to pullout for the lag screws was significantly higher than that for the novel screws.(4)The novel screw effectively repaired sacroiliac joint injuries.(5)The stiffness after repair of sacroiliac joint injuries was equivalent when using a single novel screw compared to using two lag screws.(6)These results prove that the theoretical model for the maximum resistance to pullout of the screws established in this study has a certain level of validity and can guide the design of them with improved mechanical performance.The novel sacroiliac spiral blade screw can effectively hold trabecular bone and has practical clinical utility.

Objective To investigate the nebulization characteristics of human interferon α1b for injection.To characterize and compare the delivery rate,total drug substance and the aerodynamic characteristics between the two types of nebulizer.Methods Connect two types of nebulizers with a breathing simulator,respectively,and simulate the breathing patterns of an infant and child.Measure the delivery rate,total delivered dose,and delivery uniformity.The aerodynamic properties of human interferon α1b for injection were evaluated by the next generation impactor(NGI).The content of human interferon α1b was quantified by double antibody sandwich ELISA.Results In the three batches of samples in infant mode,the delivery rate and total delivered dose determind by A nebulizer were 0.45,0.49,0.44 μg·min-1,3.06,3.21,3.81 μg,respectcively;and 0.12,0.14,0.16 μg·min-1,0.73,0.73,0.75 μg,respectcively by B nebulizer.In child mode,the delivery rate and total delivered doses determined by A nebulizer were 1.36,1.49,1.20 μg·min-1,7.44,7.17,and 6.54 μg,respectcively;and 0.37,0.36,0.43 μg·min-1,1.66,1.59,and 1.41 μg,respectcively by B nebulizer.In child and infant mode,the ten results of the total drug substance delivered determined by nebulizer A were both between 65%to 135%of the average.The FPD,FPF,MMAD,and GSD determined by A neublizer of three batch samples were 2.48,2.92,2.35 μg,59.0%,57.4%,59.1%,4.18,4.34,4.15 μm,1.94,1.98,2.01,respectively.The FPD,FPF,MMAD and GSD determined by B neublizer of three batches samples were 2.70,3.38,3.06 μg,67.6%,66.4%,66.3%,3.55,3.65,3.68 μm,2.03,2.04,2.06,respectively.Conclusions The data obtained in this research characterized the in vitro nebulization characteristics of human interferon α1b for injection and provided a theoretical basis and reference for in vitro study and clinical practice.The influence of different types of nebulizers on nebulization characteristics was evaluated as well.It is suggested that the quality standard of nebulizers be strictly formulated and the use of nebulizers be standardized.

Objective To investigate the nebulization characteristics of human interferon α1b for injection.To characterize and compare the delivery rate,total drug substance and the aerodynamic characteristics between the two types of nebulizer.Methods Connect two types of nebulizers with a breathing simulator,respectively,and simulate the breathing patterns of an infant and child.Measure the delivery rate,total delivered dose,and delivery uniformity.The aerodynamic properties of human interferon α1b for injection were evaluated by the next generation impactor(NGI).The content of human interferon α1b was quantified by double antibody sandwich ELISA.Results In the three batches of samples in infant mode,the delivery rate and total delivered dose determind by A nebulizer were 0.45,0.49,0.44 μg·min-1,3.06,3.21,3.81 μg,respectcively;and 0.12,0.14,0.16 μg·min-1,0.73,0.73,0.75 μg,respectcively by B nebulizer.In child mode,the delivery rate and total delivered doses determined by A nebulizer were 1.36,1.49,1.20 μg·min-1,7.44,7.17,and 6.54 μg,respectcively;and 0.37,0.36,0.43 μg·min-1,1.66,1.59,and 1.41 μg,respectcively by B nebulizer.In child and infant mode,the ten results of the total drug substance delivered determined by nebulizer A were both between 65%to 135%of the average.The FPD,FPF,MMAD,and GSD determined by A neublizer of three batch samples were 2.48,2.92,2.35 μg,59.0%,57.4%,59.1%,4.18,4.34,4.15 μm,1.94,1.98,2.01,respectively.The FPD,FPF,MMAD and GSD determined by B neublizer of three batches samples were 2.70,3.38,3.06 μg,67.6%,66.4%,66.3%,3.55,3.65,3.68 μm,2.03,2.04,2.06,respectively.Conclusions The data obtained in this research characterized the in vitro nebulization characteristics of human interferon α1b for injection and provided a theoretical basis and reference for in vitro study and clinical practice.The influence of different types of nebulizers on nebulization characteristics was evaluated as well.It is suggested that the quality standard of nebulizers be strictly formulated and the use of nebulizers be standardized.

BACKGROUND:The pelvis has abundant trabecular bone content,but the ability of conventional sacroiliac percutaneous fixation to control trabecular bone is limited,leading to fixation failure.Therefore,the development of devices that can more effectively control trabecular bone tension is of significant importance.OBJECTIVE:The mechanical properties of a novel sacroiliac tension screw were investigated using biomechanical testing and numerical modeling analysis,along with an assessment of the reliability of the pull-out force numerical model.METHODS:A mechanical model was established based on the working principle of the novel sacroiliac tension screw.Numerical methods were employed to analyze its pull-out performance,validated through mechanical testing with polyurethane material to assess the reliability of the pull-out force numerical model.Using pelvic specimens,the mechanical effectiveness of the novel sacroiliac tension screw in repairing sacroiliac joint injuries was analyzed under normal standing posture,along with an evaluation of the load stiffness of different pelvic models in the standing position.RESULTS AND CONCLUSION:(1)The average error between the computed values of the numerical model and the measured values was 13.19％,indicating a certain level of validity for the numerical model.(2)The damage to the polyurethane material after the extraction of the screw was less pronounced in the novel screw group.(3)The average effective holding displacement for the novel screw was approximately(9.24±0.27)mm,significantly greater than the average displacement of(1.71±0.57)mm observed with the lag screws.However,the maximum resistance to pullout for the lag screws was significantly higher than that for the novel screws.(4)The novel screw effectively repaired sacroiliac joint injuries.(5)The stiffness after repair of sacroiliac joint injuries was equivalent when using a single novel screw compared to using two lag screws.(6)These results prove that the theoretical model for the maximum resistance to pullout of the screws established in this study has a certain level of validity and can guide the design of them with improved mechanical performance.The novel sacroiliac spiral blade screw can effectively hold trabecular bone and has practical clinical utility.

BACKGROUND:Laser therapy is a non-invasive and painless treatment that is considered to be an effective method suitable for the treatment of osteoarthritis due to its simplicity and non-invasive nature.Currently,the mechanism of action of laser therapy is unclear and the results of studies on its clinical application are controversial. OBJECTIVE:To review and summarize the latest research progress of laser therapy on chondrocytes,animal experiments and clinical efficacy,and to explore the possible mechanism of laser-mediated multi-pathway biological effects,so as to provide a theoretical basis for further research on the laser treatment of osteoarthritis of the knee joint. METHODS:A literature search was performed in CNKI,WanFang Data,VIP and PubMed databases for relevant literature published from 2018 to 2023,with"laser therapy,low level laser therapy,high level laser therapy,photobiomodulation,knee osteoarthritis,chondrocytes"as the search terms in Chinese and English,respectively.Together with 14 articles searched manually,70 articles were finally included for review. RESULTS AND CONCLUSION:Laser therapy in the treatment of knee osteoarthritis is mainly categorized into two types:low-level laser therapy and high-level laser therapy.Differences in laser parameters and treatment protocols have a direct impact on laser efficacy.When appropriate parameters are used,low-level lasers show positive effects in cellular experiments,animal models,and clinical efficacy.High-level lasers have been less studied in the treatment of knee osteoarthritis,but some preliminary clinical studies have shown positive results.Cell experiments have shown that low-level laser promotes chondrocyte proliferation and cartilage matrix synthesis,thereby reducing inflammatory response.Animal experiments have shown that low-level laser can reduce the release of pro-inflammatory factors,promote cartilage matrix synthesis,inhibit matrix degradation,and effectively improve the repair process of cartilage tissue.Low-level laser is also able to reduce oxidative stress damage and relieve pain in knee osteoarthritis.In clinical trials,both low-and high-level laser can reduce patients'pain and improve functional activities.The combination of laser therapy and exercise therapy modalities may improve the therapeutic effect.Lasers may affect intracellular signaling and cellular functions through photobiological or thermodynamic effects.This provides direct evidence that laser promotes articular cartilage regeneration.

OBJECTIVE: To investigate the accuracy, safety, and short-term effectiveness of a domestic robot-assisted system in total knee arthroplasty (TKA) by a multicenter randomized controlled trial. METHODS: Between December 2021 and February 2023, 138 patients with knee osteoarthritis who received TKA in 5 clinical centers were prospectively collected, and 134 patients met the inclusion criteria were randomly assigned to either a trial group ( n=68) or a control group ( n=66). Seven patients had lost follow-up and missing data, so they were excluded and the remaining 127 patients were included for analysis, including 66 patients in the trial group and 61 patients in the control group. There was no significant difference ( P>0.05) in gender, age, body mass index, side, duration of osteoarthritis, Kellgren-Lawrence grading, preoperative Knee Society Score (KSS) and Western Ontario and McMaster University Osteoarthritis Index (WOMAC) score between the two groups. The trial group completed the TKA by domestic robot-assisted osteotomy according to the preoperative CT-based surgical planning. The control group was performed by traditional osteotomy plate combined with soft tissue release. Total operation time, osteotomy time of femoral/tibial side, intraoperative blood loss, and postoperative complications were recorded and compared between the two groups. The radiographs were taken at 5 and 90 days after operation, and hip-knee-ankle angle (HKA), lateral distal angle of femur (LDFA), and posterior tibial slope (PTS) were measured. The difference between the measured values of the above indexes at two time points after operation and the preoperative planning target values was calculated, and the absolute value (absolute error) was taken for comparison between the two groups. The postoperative recovery of lower limb alignment was judged and the accuracy was calculated. KSS score and WOMAC score were used to evaluate the knee joint function of patients before operation and at 90 days after operation. The improvement rates of KSS score and WOMAC score were calculated. The function, stability, and convenience of the robot-assisted system were evaluated by the surgeons. RESULTS: The total operation time and femoral osteotomy time of the trial group were significantly longer than those of the control group ( P<0.05). There was no significant difference in the tibial osteotomy time and the amount of intraoperative blood loss between the two groups ( P>0.05). The incisions of both groups healed by first intention after operation, and there was no infection around the prosthesis. Nine patients in the trial group and 8 in the control group developed lower extremity vascular thrombosis, all of which were calf intermuscular venous thrombosis, and there was no significant difference in the incidence of complications ( P>0.05). All patients were followed up 90 days. There was no significant difference in KSS score and WOMAC score between the two groups at 90 days after operation ( P>0.05). There was significant difference in the improvement rate of KSS score between the two groups ( P<0.05), while there was no significant difference in the improvement rate of WOMAC score between the two groups ( P>0.05). Radiological results showed that the absolute errors of HKA and LDFA in the trial group were significantly smaller than those in the control group at 5 and 90 days after operation ( P<0.05), and the recovery accuracy of lower limb alignment was significantly higher than that in control group ( P<0.05). The absolute error of PTS in the trial group was significantly smaller than that in the control group at 5 days after operation ( P<0.05), but there was no significant difference at 90 days between the two groups ( P>0.05). The functional satisfaction rate of the robot-assisted system was 98.5% (65/66), and the satisfaction rates of stability and convenience were 100% (66/66). CONCLUSION Domestic robot-assisted TKA is a safe and effective surgical treatment for knee osteoarthritis, which can achieve favorable lower limb alignment reconstruction, precise implant of prosthesis, and satisfactory functional recovery.
Humans ; Arthroplasty, Replacement, Knee/methods* ; Osteoarthritis, Knee/surgery* ; Blood Loss, Surgical ; Robotics ; Knee Joint/surgery* ; Knee Prosthesis ; Retrospective Studies

Objective:To assess the nutritional status of elderly patients with dementia in a memory clinic and to identify patients with malnutrition and patients at risk for malnutrition.Methods:A total of 510 elderly dementia patients were recruited from a memory clinic of the First Affiliated Hospital of Chongqing Medical University.All subjects were assessed with the mini-nutritional assessment short-form(MNA-SF), mini-mental state examination(MMSE), activities of daily living scale(ADL)and neuropsychiatric inventory(NPI). Logistic regression was used to explore potential risk factors and to establish a prediction model.Results:13.33%(68/510)of participants were classified as being malnourished, 52.94%(270/510)as being at risk for malnutrition and 33.73%(172/510)as well nourished.A Logistic regression model for predicting malnutrition identified dysphagia, irritability, physical self-maintenance scale(PSMS), appetite and eating disorders as important influencing factors( OR=4.334, 1.096, 1.121, 1.213, all P<0.05), and MMSE score, family history of dementia and age were important influencing factors for predicting malnutrition/at risk for malnutrition( OR=0.923, 0.517, 1.045, all P<0.05). Conclusions:The incidence of malnutrition and the risk of malnutrition in elderly patients with dementia in the memory clinic are high, and there are many related influencing factors.Early detection and intervention can delay or avoid malnutrition.

Objective:To evaluate the application value of conventional echocardiography and two-dimensional speckle tracking imaging (2D-STI) in assessing the left ventricular systolic and diastolic functions in patients with restrictive cardiomyopathy (RCM).Methods:Fifteen patients confirmed as RCM by cardiac magnetic resonance imaging or pathological biopsy in Fuwei Cardiovascular Hospital of Yunnan Province from September 2017 to June 2020 were selected. According to left ventricular ejection fraction(LVEF), they were divided into LVEF retention group(LVEF≥50%, 8 cases) and LVEF reduction group (LVEF<50%, 7 cases). Meanwhile, 20 healthy volunteers were selected as the control group. Conventional echocardiography and 2D-STI were used to evaluate left ventricular systolic and diastolic function, including left ventricular end-diastolic diameter (LVEDd), LVEF, mitral valve blood flow spectrum peak E/peak A, peak E deceleration time (EDT), tissue Doppler mitral valve ring average early diastolic peak velocity (e′), E/e′ ratio, isovolumetric relaxation time (IVRT), left atrial volume index (LAVI) and speed of tricuspid regurgitation (TVR), tricuspid annular plane systolic excursion (TAPSE), left ventricular longitudinal strain (LS) and circumferential strain (CS). Then the differences and similarities between the two RCM groups and the control group were compared.Results:There was no significant difference of LVEF between LVEF retention group and the control group ( P>0.05), and LVEF in LVEF reduction group was significantly lower than that in control group ( P<0.05). LVEDd in LVEF retention group was significantly smaller than that of LVEF reduction group ( P<0.05), but was not statistically different from the control group ( P>0.05). Values of E/A, E/e′, LAVI and TVR in LVEF retention group and LVEF reduction group were significantly greater than the control group (all P<0.05), and there was no statistically significant difference between the two RCM groups ( P<0.05). Values of e′, EDT, IVRT and TAPSE in LVEF retention group and LVEF reduction group were significantly lower than the control group (all P<0.05), and there was no statistically significant difference between the two RCM groups (all P>0.05). The global LS and LS of AP4, AP3, and AP2 showed significantly different among the 3 groups (all P<0.05). The global and basal, middle, apical segmental CS in LVEF retention group were significantly larger than those in LVEF reduction group (all P<0.05), but they were not significantly different from the control group (all P>0.05). Conclusions:All patients with RCM show left ventricular diastolic dysfunction in conventional echocardiography, and show gradually reduced left ventricular systolic function and left ventricular remodeling. RCM patients with normal LVEF demonstrate decreased myocardial systolic function, and left ventricular global LS could be used as a sensitive indicator to predict myocardial systolic function.

Pre-hospital rescue is key to the emergency medical system. Based on the current pre-hospital emergency standardized system construction in China, the authors explored the standardization of pre-hospital emergency system construction, command dispatch and emergency service quality control standardization, pre-hospital classification standardization, pre-hospital emergency service capacity standardization, pre-hospital emergency and intra-hospital emergency connection standardization, standardized training for pre-hospital emergency doctors and nurses. These efforts aim to achieve such rescue and transfer criteria for patients, as " vicinity, urgency, professional needs, and intension of both patients and their families" . Such criteria if met can further reduce emergency response time and shorten the emergency radius, hence improving emergency medical services.

Objective: To detect the possible molecular mechanisms of the formation of vessels that encapsulated tumor clusters (VETC) and identify the relationship between vimentin protein expression in endothelial cells and contrast-enhanced ultrasound characters in VETC (+ ) hepatocellular carcinoma (HCC). Methods: A total of 64 paraffin embedded HCC tissue samples were collected, all of which the tumor diameters were between 2 cm and 5 cm measured by the preoperative ultrasound. Immunohistochemistry staining for CD34 was used to detect the formation of VETC and the expressions of angiopoietin-2 (Ang-2) and vimentin were also determined. Human umbilical vein endothelial cells (HUVECs) were treated with 150 ng/ml recombinant human Ang-2 protein (rhAng-2) at various times and the protein expression of vimentin was detected by western blot assay. The contrast-enhanced ultrasound characters were also analyzed in both VETC (+ ) and VETC (-) HCC. Results: Tumor clusters encapsulated by vessels to form cobweb-like networks, which were identified as VETC phenotype, were observed in 27 HCC tissues (42.18%). In VETC (+ ) HCC tissues, Ang-2 was overexpressed in tumor cells and endothelial cells while vimentin was only upregulated in endothelial cells. With the treatment of 150 ng/ml rhAng-2 protein, the expression of vimentin in HUVECs was 0.878±0.102 and 0.918±0.092 at 12 h and 36 h, significantly upregulated when compared to the 0.322±0.061 at 6 h (P<0.01). In contrast-enhanced ultrasound, a crack and tendon-like filling character was observed in VETC (+ ) HCC during the arterial-phase, while the large scale and diffuse-like filling character was observed in VETC (-) HCC. The filling time of unit diameter in VETC (+ ) HCC was (3.95±0.22)s, significantly longer than (2.28±0.27)s of VETC (-) HCC (P<0.01). Conclusions The overexpressions of Ang-2 and vimentin are positively correlated with the formation of VETC and considered as potential therapeutic targets of VETC (+ ) HCC. The crack and tendon-like filling characters in arterial-phase of contrast-enhanced ultrasound indicates the VETC (+ ) HCC.