Objective: To study changes of ultrastructure of atrial endothelial cells during acute atrial fibrillation (AF) in canines, and explore the possible mechanism of AF left atrial thrombosis. Methods: A total of 16 healthy adult mongrel canines were randomly and equally divided into blank control group (only received thoracotomy without pacing) and rapid atrial pacing (RAP) group (established acute AF model). Myocardial tissue of left and right appendage were taken from two groups and received hematoxylin eosin (HE) staining, then myocardial cell morphological changes was observed under ordinary light microscope; morphological changes of appendage endothelial cells was observed under electron microscope. Results: (1) Paroxysmal AF was successfully induced in all canines of RAP group; (2) There were no significant difference in morphology of appendage and endocardial tissue under ordinary light microscope between two groups; 3. Under transmission electron microscope, endothelium cell of appendage tissue presented defect of different extent, and some shedding in RAP group; while endothelial cell layer was complete with absence of necrosis and shedding in blank control group. Compared with blank control group, there was significant rise in endothelial cell incompleteness (12.5% vs. 75.0%) in RAP group, P=0.041. Conclusion: When acute atrial fibrillation occurs, endothelial cell ultrastructure has already changed, which may be related to thrombosis adhered to wall during atrial fibrillation.

The gene encoding selenoprotein phospholipid hydroperoxide glutathioneperoxidase (PHGPx) is located in chromosome 19 in human. PHGPx is the secondidentified as Se-dependent intracellular glutathione peroxidase (PHGPx) which is a19000(Mr), monomeric enzyme. PHGPx originally presumed to be a universal antioxidantenzyme protecting membrane lipids, appears to have adopted a variety of specificroles like silencing lipoxygenases and becoming an enzymatically inactive structuralcomponent of the mitochondrial capsule during sperm maturation. In other words,PHGPx exists as a soluble peroxidase in spermatids but persists in maturespermatozoa as an enzymatically inactive, oxidatively cross-linked, insolubleprotein. Natl J Androl,2001,7(2):109～112

[Objective] To evaluate the effect of fast rehabilitation nursing pathway in patients after artificial hip replacement.[Methods] 86 patients underwent artificial hip replacement were randomly divided into the control group and the experimental group with 43 cases in each group.The control group received routine care,while the experimental group was given fast rehabilitation nursing pathway.Anxiety and pain at 48h after operation were evaluated,and hip joint function(Harris score)was evaluated six months after operation.[Results] Compared with the control group,anxiety and pain score at 48h after operation decreased markedly,and Harris score six months after operation increased significantly.[Conclusions] Fast rehabilitation nursing pathway can reduce both the short-term and long-term efficacy of patients after artificial hip replacement.

Objective:To investigate the application value and clinical effect of tissue expansion in post-mastectomy breast reconstruction.Methods:From January 2013 to May 2019, 173 patients (38.2±8.0 years old) with body mass index (BMI) of (21.5±2.1) kg/m 2 were treated in Peking University Third Hospital. There were 76 cases on the right side and 97 cases on the left side; 8 cases underwent nipple sparing mastectomy, and 165 cases underwent modified radical mastectomy; 150 cases received chemotherapy and 9 cases received radiotherapy. In the first stage, immediate or delayed chest wall soft tissue expansion was performed. In the second stage, implant replacement, autologous tissue transplantation, or the combination of these two methods was performed to complete the breast reconstruction. All patients were followed up and the clinical effect was evaluated by Harris evaluation method. Results:Among 173 cases, 95 cases were provided immediate reconstruction, and 78 cases were applied delayed reconstruction. The period of tissue expansion was (7.7±3.2) months. During the second stage of reconstruction, implant exchange was conducted in 105 cases, 48 cases received implant exchange with autologous fat injection, 17 cases were performed implant exchange with endoscopy-assisted latissimus dorsi muscle transfer, and 3 cases were applied deep inferior epigastric perforator flap (DIEP) transplantation. The average follow-up time was 12.6 months (3.5-41.0 months). One patient had local tumor recurrence, and the implant was finally removed. The reconstruction effects were evaluated by Harris method, which showed that 23 cases had excellent appearance, 129 cases were good, 13 cases were fair, 7 cases were poor, and 88.4% (152/172) patients were good or above.Conclusions:Tissue expansion plays an important role as a transfer station in post-mastectomy breast reconstruction. In the second stage, the breast reconstruction method can be flexibly selected. Tissue expansion has a wide range of indications, and is especially suitable for immediate post-mastectomy breast reconstruction. Good result can be obtained by using this technique.

Objective:To investigate the application value and clinical effect of tissue expansion in post-mastectomy breast reconstruction.Methods:From January 2013 to May 2019, 173 patients (38.2±8.0 years old) with body mass index (BMI) of (21.5±2.1) kg/m 2 were treated in Peking University Third Hospital. There were 76 cases on the right side and 97 cases on the left side; 8 cases underwent nipple sparing mastectomy, and 165 cases underwent modified radical mastectomy; 150 cases received chemotherapy and 9 cases received radiotherapy. In the first stage, immediate or delayed chest wall soft tissue expansion was performed. In the second stage, implant replacement, autologous tissue transplantation, or the combination of these two methods was performed to complete the breast reconstruction. All patients were followed up and the clinical effect was evaluated by Harris evaluation method. Results:Among 173 cases, 95 cases were provided immediate reconstruction, and 78 cases were applied delayed reconstruction. The period of tissue expansion was (7.7±3.2) months. During the second stage of reconstruction, implant exchange was conducted in 105 cases, 48 cases received implant exchange with autologous fat injection, 17 cases were performed implant exchange with endoscopy-assisted latissimus dorsi muscle transfer, and 3 cases were applied deep inferior epigastric perforator flap (DIEP) transplantation. The average follow-up time was 12.6 months (3.5-41.0 months). One patient had local tumor recurrence, and the implant was finally removed. The reconstruction effects were evaluated by Harris method, which showed that 23 cases had excellent appearance, 129 cases were good, 13 cases were fair, 7 cases were poor, and 88.4% (152/172) patients were good or above.Conclusions:Tissue expansion plays an important role as a transfer station in post-mastectomy breast reconstruction. In the second stage, the breast reconstruction method can be flexibly selected. Tissue expansion has a wide range of indications, and is especially suitable for immediate post-mastectomy breast reconstruction. Good result can be obtained by using this technique.

Objective To investigate the characteristics of knee kinematics and ground reaction force (GRF), as well as the stress state of cartilage and meniscus in the process of lateral incisions at different cutting angles under expected conditions. Methods Kinematics and GRF data of 14 subjects at 45°, 90° and 135° cutting angle respectively under expected conditions were collected. The knee joint reaction force was obtained through the inverse dynamics calculation of Visual 3D. Based on three-dimensional (3D) finite element model of the knee joint, the contact process at 3 lateral cutting angles was simulated. ResultsUnder expected conditions, there were significant differences in knee joint kinematics characteristics at 3 cutting angles during contact process(P＜0.001), and the knee flexion increased with the cutting angle increasing; the vertical GRF decreased significantly with the cutting angle increasing (P＜0.001), while the horizontal GRF showed the opposite trend; for 3 cutting angles, the peak contact stress of patellar cartilage and femoral cartilage was larger at 90° cutting angle, the peak principal stress at anterior cruciate ligament (ACL) contact point was also larger at 90° cutting angle, and the following was at 135° and 45° cutting angle, respectively; the peak contact stress of lateral femoral cartilage was larger than that of medial femoral cartilage at 3 cutting angles. Conclusions The risk of knee joint injury is higher at 90° cutting angle, and the stress state of knee joint at 135° cutting angles is better than that at 90° cutting angle, and the risk of knee joint injury does not increase with the increase of cutting angle under expected conditions.

Objective To discuss rationality of the three-link model used in analysis on interactive dynamics of deep squatting, and clarify the source of differences in calculation of joint torque by three-link model and Visual 3D. Methods Eight subjects were selected to obtain kinematic data of the squat motion through Vicon. The second Lagrangian equation was used to establish the three-link dynamic equation. The joint torque was calculated based on the Mathematica programming. The results were compared with the calculation results of lower limb chain segment model by Visual 3D, and the similarity between the two results was evaluated by the coefficient of complex correlation (CMC). Results The CMC of hip joint and knee joint from 8 subjects was larger than 0.85, and the CMC of ankle joint was between 0.50-0.85. The joint torque calculated by three-link dynamic equation and Visual 3D was highly similar in hip joint and knee joint, and there was only a moderate similarity in ankle joint. Conclusions The three-link model can be used in further analysis on interactive dynamics of deep squatting, but the influence of interactive moment caused by ground reaction force (external moment) on ankle torque should be considered.

To study the change of the dominant eye in the age-related cataract patients before and after surgery, to analyze the correlation between the orientation of the dominant eye and the visual quality, and to observe whether the patients with the change in dominant eye were converted to dizziness.
 Methods: A total of 44 patients, with age-related cataract between 60 and 80 years old were enrolled. Group A: the non-dominant (secondary) eye served as the surgical eye (n=35); Group B: the dominant eye served as the surgical eye (n=9); Group C: the operation was performed on the contralateral eye after a month (n=28). Measurement of the dominant eye was performed before operation, 1 week after operation and 1 month after the operation. The changes in the uncorrected distance visual acuity (UCDVA), contrast sensitivity (CS), best corrected visual acuity (BCVA) and spherical equivalent (SE) between the dominant and non-dominant eye were compared.
 Results: The UCDVA, CS, BCVA and SE were significantly improved at 1 day after the operation. There was significant difference between the 2 groups (P<0.05). Preoperative: in group A, the UCDVA, CS, BCVA of ocular dominance were better than the non-dominant eye with significant difference (P<0.05), while there was no significant difference between the SE (P>0.05); in group B, the UCDVA, CS, BCVA in the dominant eye were better than the non-dominant eye's, but the difference was not statistically significant (P>0.05). After operation: the UCDVA, CS and BCVA in the dominant eye in group A and group B were higher than those of the non-dominant eye with statistical difference (P<0.05), but there was no statistical difference between SE (P>0.05). The dominant eye's transformation occurred in group A when the non-dominant eye's postoperative visual quality improved over the leading eye. The transformation rate was 60% in 1 week, and the conversion rate was 80% in 1 month. In group C, the dominant eye reduction rate was 100%, and the visual quality was not significant difference between the two eyes (P>0.05). After the operation, the patients with the dominant eye's transformation felt discomfort, which could be relieved within 1 week.
 Conclusion: The location of the dominant eye was correlated with uncorrected visual acuity, contrast sensitivity, and the best corrected visual acuity. The dominant eye's transformation occurred when the non-dominant eye's postoperative visual quality improved over the leading eye after the surgery. If the contralateral eye's surgery was performed in a short term, the dominant eye can be returned to the initial state.
Aged ; Aged, 80 and over ; Cataract ; therapy ; Cataract Extraction ; Humans ; Middle Aged ; Phacoemulsification ; Treatment Outcome ; Visual Acuity