The long service life and high reliability of SiC sliding bearings are crucial for the long-term normal operation of aerospace power equipment.In response to the fracture phenomenon observed in the sliding bearing assembly of a certain delivery pump during operation,this paper analyzes the issue from the perspectives of stress characteristics and thermal expansion effects,proposing a structural optimization design method based on temperature coefficient compensation.The research indicates that the primary cause of bearing fracture is the difference in thermal expansion coefficients between the bearing and the metal rotor under elevated temperatures,leading to axial loosening of the bearing.Additionally,the gap between the bearing and the pin,combined with unstable lubrication of the friction pair,exacerbates bearing stalling and pin impact,ultimately causing cracks and localized chipping.By optimizing the bearing structure and employing a rubber pad for torque transmission,this issue has been successfully resolved.The improved structure demonstrated high reliability and stability in bench tests,providing important theoretical and technical references for the design of bearings under similar extreme operating conditions.

Objective:To evaluate the role of spinal Annexin A3 (ANXA3) in neuropathic pain in mice.Methods:Sixty-four SPF healthy adult male C57BL/6 mice, weighing 22-26 g, aged 8-10 weeks, were divided into 4 groups ( n=16 each) by the random number table method: sham operation group (group S), chronic constriction injury (CCI) group, CCI+ negative control adeno-associated virus AAV-NC group (group CCI+ N) and CCI+ adeno-associated virus AAV-shANXA3 group (group CCI+ sh). The neuropathic pain was induced by CCI of the sciatic nerve in anesthetized animals. The AAV-shANXA3 and AAV-NC (5 μl) were intrathecally injected at 14 days before developing the model in CCI+ N group and CCI+ sh group. The mechanical paw withdrawal threshold (MWT) and thermal paw withdrawal latency (TWL) were measured at 1 day before developing the model and at 7, 14 and 21 days after developing the model. All the mice were sacrificed after the last measurement of pain threshold, the L 4-6 segments of the spinal cord were removed for determination of the expression of ANXA3, phosphorylated nuclear factor-kappa B (p-NF-κB) and ionized calcium-binding adaptor molecule-1 (Iba-1)(by Western blot), expression of ANXA3 mRNA (by real-time polymerase chain reaction), microglial activation (using the immunofluorescence staining), and contents of pro-inflammatory cytokines tumor necrosis factor-alpha (TNF-α), interleukin-1beta (IL-1β) and IL-6 and anti-inflammatory cytokines transforming growth factor-beta (TGF-β) and IL-10 (using enzyme-linked immunosorbent assay). Results:Compared with group S, the MWT was significantly decreased and TWL was shortened after developing the model, the expression of ANXA3 protein and mRNA, p-NF-κB and Iba-1 in spinal cord was up-regulated, the contents of TNF-α, IL-1β and IL-6 were increased, the contents of TGF-β and IL-10 were decreased ( P<0.05), the activation of microglia in the spinal cord was significantly increased, and the cell body was enlarged in group CCI. There was no significant difference in each parameter between group CCI and group CCI+ N ( P>0.05). Compared with CCI+ N group, the MWT was significantly increased on days 14 and 21 after developing the model, the TWL was prolonged on day 21 after developing the model, the expression of ANXA3 protein and mRNA, p-NF-κB and Iba-1 was down-regulated, the contents of TNF-α, IL-1β and IL-6 were decreased, the contents of TGF-β and IL-10 were increased ( P<0.05), and the activation of spinal microglia was decreased in CCI+ sh group. Conclusions:Spinal ANXA3 may be involved in the development and maintenance of neuropathic pain by activating the NF-κB signaling pathway and further promoting microglial activation in mice.

Turning to critical illness is a common stage of various diseases and injuries before death. Patients usually have complex health conditions, while the treatment process involves a wide range of content, along with high requirements for doctor′s professionalism and multi-specialty teamwork, as well as a great demand for time-sensitive treatments. However, this is not matched with critical care professionals and the current state of medical care in China. Telemedicine, which shortens the distance of medical professionals and the gap of disease diagnosis and treatments in various regions through electronic information, can effectively solve the current problem. Therefore, there is an urgent need to develop a standardized, high-quality visualization telemedicine round system .Therefore, experts have been organized to search domestic and foreign literature on telemedicine round for critically ill patients and to form this consensus based on clinical experiences so as to further improve the level of critical care treatments in regions.

Objective:To investigate the clinical efficacy of minimally invasive percutaneous internal fixation with double screws for delayed union or nonunion of scaphoid fracture.Methods:A retrospective study was conducted to analyze the 12 patients with delayed union or nonunion of scaphoid fracture who had been treated at Department of Hand and Foot Surgery, The Affiliated Hospital of Jining Medical University from March 2021 to December 2023. They were 11 males and 1 female, with an age of (29.9±13.8) years and an interval from injury to surgery of (5.1±2.6) months. They were all treated by minimally invasive percutaneous internal fixation with 2 hollow compression screws. The visual analogue scale (VAS), grip strength (percentage of the affected side to the healthy side), wrist range of motion, modified Mayo wrist score and other data were recorded and compared between pre-surgery and the last follow-up. The incidence of complications was recorded.Results:Follow-up for all patients lasted for (20.8±8.9) months. All patients achieved bony union after (10.1±3.2) weeks with no complications like infection. No post-surgery imaging revealed screw misplacement or penetration. At the last follow-up, the VAS pain score was 0 (0, 1) point, the wrist grip strength 100.6%±7.2%, the wrist flexion 88.3°±2.5°, the wrist dorsiflexion 88.5°±2.2°, and the modified Mayo wrist score (98.3±2.5) points, all significantly better than the pre-surgery values [4 (4, 5) points, 69.1%±16.0%, 61.3°±13.5°, 64.7°±9.1°, and (61.7±10.1) points] (all P < 0.05). Conclusion:In the treatment of delayed union or nonunion of scaphoid fracture, minimally invasive percutaneous internal fixation with double screws shows advantages of minimal invasion, quick fracture healing, fine functional recovery, and no need of bone grafting.

Objective To assess the incidence of contrast-induced nephropathy(CIN)in patients with chronic thromboembolic pulmonary hypertension(CTEPH)after receiving balloon pulmonary angioplasty(BPA),and to evaluate the effect of the contrast agents on renal function.Methods A total of 143 CTEPH patients,who received BPA at the China-Japan Friendship Hospital of China from December 2018 to May 2022,were enrolled in this study.The clinical data,hemodynamic indicators,and serum creatinine(SC)concentrations within one week before and 48-72 h after BPA were collected.The estimated glomerular filtration rate(eGFR)was calculated according to the Modification of Diet in Renal Disease(MDRD)formula.The SC concentration and eGFR changes before and after each BPA procedure were compared.The incidence of CIN and its risk factors were evaluated,and the changes in hemodynamics,SC and eGFR after the initial and last time of BPA treatment were analyzed.Results A total of 192 BPA procedures were performed in 115 CTEPH patients,including 88 BPA procedures in males and 103 BPA procedures in females.The mean amount of contrast agent used for each BPA was(145.58±47.26)mL.After BPA,12 patients developed 13 times of CIN,with an incidence of 6.8％.There was no significant differences(P＞0.05)in the baseline characteristics and SC concentration before BPA between CIN patients and non-CIN patients.In terms of the hemodynamic indexes,the mixed venous oxygen saturation(SvO2)in CIN patients was significantly lower than that in non-CIN patients(58.58％±10.38％vs.66.15％±8.02％,P=0.002),and no statistically significant differences(P＞0.05)in the other hemodynamic indexes existed between CIN group and non-CIN group.No statistically significant differences in SC concentration and eGFR existed before and after each BPA procedure.In patients who had received several BPA procedures,significant improvements in the SC[(78.09±18.760)μmol/L vs.(82.26±21.37)μmol/L,P＜0.001]and eGFR[(86.08±21.22)mL/(min·1.73 m2)vs.(82.07±22.05)mL/(min·1.73 m2),P=0.007]was achieved when compared with their baseline values.Conclusion CTEPH patients may develop CIN after receiving BPA treatment.After receiving several BPA treatments the patient's clinical symptoms and hemodynamics can be improved,and the patient's renal function is also significantly improved.

Objective:To evaluate the role of spinal Annexin A3 (ANXA3) in neuropathic pain in mice.Methods:Sixty-four SPF healthy adult male C57BL/6 mice, weighing 22-26 g, aged 8-10 weeks, were divided into 4 groups ( n=16 each) by the random number table method: sham operation group (group S), chronic constriction injury (CCI) group, CCI+ negative control adeno-associated virus AAV-NC group (group CCI+ N) and CCI+ adeno-associated virus AAV-shANXA3 group (group CCI+ sh). The neuropathic pain was induced by CCI of the sciatic nerve in anesthetized animals. The AAV-shANXA3 and AAV-NC (5 μl) were intrathecally injected at 14 days before developing the model in CCI+ N group and CCI+ sh group. The mechanical paw withdrawal threshold (MWT) and thermal paw withdrawal latency (TWL) were measured at 1 day before developing the model and at 7, 14 and 21 days after developing the model. All the mice were sacrificed after the last measurement of pain threshold, the L 4-6 segments of the spinal cord were removed for determination of the expression of ANXA3, phosphorylated nuclear factor-kappa B (p-NF-κB) and ionized calcium-binding adaptor molecule-1 (Iba-1)(by Western blot), expression of ANXA3 mRNA (by real-time polymerase chain reaction), microglial activation (using the immunofluorescence staining), and contents of pro-inflammatory cytokines tumor necrosis factor-alpha (TNF-α), interleukin-1beta (IL-1β) and IL-6 and anti-inflammatory cytokines transforming growth factor-beta (TGF-β) and IL-10 (using enzyme-linked immunosorbent assay). Results:Compared with group S, the MWT was significantly decreased and TWL was shortened after developing the model, the expression of ANXA3 protein and mRNA, p-NF-κB and Iba-1 in spinal cord was up-regulated, the contents of TNF-α, IL-1β and IL-6 were increased, the contents of TGF-β and IL-10 were decreased ( P<0.05), the activation of microglia in the spinal cord was significantly increased, and the cell body was enlarged in group CCI. There was no significant difference in each parameter between group CCI and group CCI+ N ( P>0.05). Compared with CCI+ N group, the MWT was significantly increased on days 14 and 21 after developing the model, the TWL was prolonged on day 21 after developing the model, the expression of ANXA3 protein and mRNA, p-NF-κB and Iba-1 was down-regulated, the contents of TNF-α, IL-1β and IL-6 were decreased, the contents of TGF-β and IL-10 were increased ( P<0.05), and the activation of spinal microglia was decreased in CCI+ sh group. Conclusions:Spinal ANXA3 may be involved in the development and maintenance of neuropathic pain by activating the NF-κB signaling pathway and further promoting microglial activation in mice.

Turning to critical illness is a common stage of various diseases and injuries before death. Patients usually have complex health conditions, while the treatment process involves a wide range of content, along with high requirements for doctor′s professionalism and multi-specialty teamwork, as well as a great demand for time-sensitive treatments. However, this is not matched with critical care professionals and the current state of medical care in China. Telemedicine, which shortens the distance of medical professionals and the gap of disease diagnosis and treatments in various regions through electronic information, can effectively solve the current problem. Therefore, there is an urgent need to develop a standardized, high-quality visualization telemedicine round system .Therefore, experts have been organized to search domestic and foreign literature on telemedicine round for critically ill patients and to form this consensus based on clinical experiences so as to further improve the level of critical care treatments in regions.

Objective:To investigate the clinical efficacy of minimally invasive percutaneous internal fixation with double screws for delayed union or nonunion of scaphoid fracture.Methods:A retrospective study was conducted to analyze the 12 patients with delayed union or nonunion of scaphoid fracture who had been treated at Department of Hand and Foot Surgery, The Affiliated Hospital of Jining Medical University from March 2021 to December 2023. They were 11 males and 1 female, with an age of (29.9±13.8) years and an interval from injury to surgery of (5.1±2.6) months. They were all treated by minimally invasive percutaneous internal fixation with 2 hollow compression screws. The visual analogue scale (VAS), grip strength (percentage of the affected side to the healthy side), wrist range of motion, modified Mayo wrist score and other data were recorded and compared between pre-surgery and the last follow-up. The incidence of complications was recorded.Results:Follow-up for all patients lasted for (20.8±8.9) months. All patients achieved bony union after (10.1±3.2) weeks with no complications like infection. No post-surgery imaging revealed screw misplacement or penetration. At the last follow-up, the VAS pain score was 0 (0, 1) point, the wrist grip strength 100.6%±7.2%, the wrist flexion 88.3°±2.5°, the wrist dorsiflexion 88.5°±2.2°, and the modified Mayo wrist score (98.3±2.5) points, all significantly better than the pre-surgery values [4 (4, 5) points, 69.1%±16.0%, 61.3°±13.5°, 64.7°±9.1°, and (61.7±10.1) points] (all P < 0.05). Conclusion:In the treatment of delayed union or nonunion of scaphoid fracture, minimally invasive percutaneous internal fixation with double screws shows advantages of minimal invasion, quick fracture healing, fine functional recovery, and no need of bone grafting.

Objective:To investigate the values of two-dimensional and three-dimensional echocardiographic parameters in predicting pulmonary vascular resistance (PVR) in chronic pulmonary thromboembolic pulmonary hypertension (CTEPH).Methods:A total of 141 patients diagnosed with CTEPH in China-Japan Friendship Hospital from November 2015 to December 2022 were included. Two-dimensional echocardiographic indicators reflecting PVR were constructed according to the calculation formula of PVR: echocardiographic estimated systolic pulmonary artery pressure (sPAP Echo)/left ventricular end-diastolic diameter (LVIDd), echocardiographic estimated mean pulmonary artery pressure (mPAP Echo)/LVIDd. sPAP Echo/left ventricular end-diastolic volume (LVEDV), sPAP Echo/left ventricular cardiac output (LVCO) were measured by three-dimensional echocardiography. The correlations between two-dimensional and three-dimensional echocardiographic ratios and invasive PVR were then analyzed using the Spearman correlation method. Using receiver operating characteristic curve analysis, cut-off values for the ratios were generated to identify patients with PVR>1 000 dyn·s -1·cm -5. Pre- and postoperative hemodynamics and echocardiographic data were analyzed, as well as the correlation between the reduction rate of the echocardiographic index and PVR in 54 patients who underwent pulmonary endarterectomy (PEA). Results:sPAP Echo/LVIDd, sPAP Echo/LVEDV and sPAP Echo/LVCO were moderately correlated with PVR( rs=0.62, 0.52, 0.63, both P<0.001). The ratio of sPAP Echo to LVEDV, when greater than or equal to 1.41, had a sensitivity of 0.800 and a specificity of 0.930 for determining PVR >1 000 dyn·s -1·cm -5 (AUC=0.860, P<0.001). Similarly, the ratio of sPAP Echo to LVIDd, when greater than or equal to 2.14, had a sensitivity of 0.647 and a specificity of 0.861 for determining PVR >1000 dyn·s -1·cm -5 (AUC=0.830, P<0.001). The sPAP Echo/LVIDd and mPAP Echo/LVIDd significantly decreased after PEA (both P<0.001). The sPAP Echo/LVIDd and mPAP Echo/LVIDd reduction rate (ΔsPAP Echo/LVIDd and ΔmPAP Echo/LVIDd) were significantly correlated with PVR reduction rate (ΔPVR), respectively ( rs=0.61, 0.63, both P<0.05). Conclusions:Two-dimensional ratio sPAP Echo/LVIDd and three-dimensional ratio sPAP Echo/LVEDV can be used to noninvasively estimate PVR in CTEPH patients. The conventional ratio sPAP Echo/LVIDd is convenient and reproducibly suitable for monitoring the improvement of PVR before and after treatment, and its ratio of 2.14 can predict the significant increase of PVR in CTEPH patients (>1 000 dyn·s -1·cm -5).

Objective:To investigate the safety and efficacy of balloon pulmonary angioplasty (BPA) for residual pulmonary hypertension (PH) of chronic thromboembolic pulmonary hypertension(CTEPH) after pulmonary endarterectomy (PEA).Methods:Patients diagnosed as PH after PEA in China-Japan Friendship Hospital from Oct 2016 to Jun 2022 were included. The indication for BPA was decided on the basis of a consensus of the multi-disciplinary team for all patients with CTEPH. Before treatment, the patient′s exercise tolerance and pulmonary artery flow parameters were evaluated. A comparative analysis of various parameters before BPA treatment and at the last BPA was conducted. 6-min walk distance (6MWD) was analyzed using the paired Wilcoxon test; N-terminal pro-brain natriuretic peptide (NT-proBNP), mixed venous oxygen saturation, mean pulmonary arterial pressure (mPAP), cardiac index (CI) and pulmonary vascular resistance (PVR) were compared using the paired-samples t-test. WHO functional class was compared using McNemar′s test. Results:Twenty patients with a total of 130 vessels underwent 46 sessions of BPA treatment. The postoperative 6-minute walk distance (6MWD) [447 (415, 485) m] showed a significant improvement compared to the preoperative baseline [389 (335, 470) m] ( Z=6.52, P<0.05), Postoperative mixed venous oxygen saturation (72.0%±1.9%) showed a significant improvement compared to the preoperative levels (64.0%±2.7%) ( t=2.14, P<0.05).Postoperatively, plasma NT-proBNP [(351.9±129.9) pg/ml], mPAP [(24.2±1.9) mmHg], and PVR [(3.0±1.4) WU] significantly decreased compared to preoperative levels [(982.5±426.2) pg/ml, (33±2.1) mmHg, (8.0±1.6) WU)] ( t=3.38, 1.22, 2.10, P<0.05 for all). Postoperatively, there was a significant improvement in WHO functional class (Ⅰ，Ⅱ，Ⅲ，Ⅳ: 14, 4, 2, 0 cases) compared to preoperative status (Ⅰ，Ⅱ，Ⅲ，Ⅳ: 0, 13, 5, 2 cases) ( χ2=20.17, P<0.05). Four cases of pulmonary artery dissection and one episode of hemoptysis occurred postoperatively, with no other complications reported. Conclusions:BPA can significantly improve exercise tolerance and hemodynamic parameters for residual PH after PEA. BPA is a relatively safe and effective treatment for residual PH after PEA.