To investigate the effects of augmentation with bone cement on the biomechanics of the dynamic hip screw (DHS) fixation in the intertrochanteric fracture specimen that has a normal bone density.MethodsTwentyfour matched pairs of the embalmed male upper femora (48sides) were used to make the specimens of the intertrochanteric fracture of Type A2. All the specimens were fixed with DHS. The right femur specimen from each pair was fixed by augmentation with DHS (the augmentation group) and the left femur specimen was fixed with the conventional fixation (the control group). Thebiomechanical tests on the bending stiffness and the torsional stiffness were performed with the servohydraulic testing machine in the two groups.ResultsThe maximum load and the maximum torque were 3 852.160 2±143.603 1 N and 15.5±2.6 Nm in the augmentation group and 3 702.966 7±133.860 1 N and 14.7±3.4 Nm in the control group. There was no significant difference in the biomechanical effects between the two groups (P＞0.05). Conclusion The augmenting fixation with bone cement in the intertrochanteric fracture specimen with a normal bone density has no significant effect on the strength of the DHS augmentation or on the overall stability of the fractured bone.
Objective To analyze the dynamic efficiency of township hospitals. Methods Based on the DEA-Malmquist index, this research analyzed the change of the total factor productivity indices and the decomposition items of 281 township hospitals in Hunan province with panel data from 2000 to 2008. Results Among 281 township hospitals, less than half increased their scale efficiency, while more than half increased their total factor productivity, technology, whole efficiency and technical efficiency. Increasing technology and whole efficiency was the best way to improve total factor productivity. Besides, increasing technical efficiency and scale efficiency was the best way to improve whole efficiency. Conclusions The improvement of scale efficiency is key to developing the central township hospitals, while the improvement of technology is the key to developing general township hospitals.
Objective To investigate the development of dynamic hipscrew (DHS) internal fixation in the treatment of intertrochanteric femur fractures. Methods The latest relevant articles were reviewed extensively, including biomechanics and clinical application research. Results DHS is the effective selection for the treatment of intertrochanteric femur fractures, especially by the innovation of DHS structure, operative manipulation.Conclusion Treatment of intertrochanteric femur fractures with DHS is still a gold level, but strict selection of patients, proficiency operation and invasive manipulation are the most essential principles.
OBJECTIVE: To study the changes of neural electrophysiology properties of cauda equina under double level compression and dynamic burdens, and to clarify the mechanisms of intermittent neurogenic claudication. METHODS: Thirty SD rats were divided into 5 groups (6 in each group). The laminectomy of L5 was performed in control group. In the experimental groups, the silicon sheets were inserted into the spinal canal of L4 and L6 to cause double level compression of cauda equina by 30%. Two hours after onset of compression, no dynamic burden was introduced in experimental group 1. Only high frequency stimulation(HFS) was introduced for 6 minutes in experimental group 2. Both HFS and additional increased compression were introduced for 6 minutes in experimental group 3. While only additional increased compression was introduced for 6 minutes in experimental group 4. After 6 minutes of dynamic burdens, all were returned to the status of static compression for another 30 minutes and then electrical examination was made. RESULTS: After 2 hours of compression, motor and sensory nerve conduction velocity (NCV) of all the four experimental groups decreased significantly (P lt; 0.05), but there was no significant difference between them. There was no significant change in the control group. There was no significant change of NCV in experimental group 1 during the last 30 minutes of experiment. NCV in the other three experimental groups decreased after introduction of dynamic burdens, especially in the experimental group 3. CONCLUSION: The above results showed that NCV of cauda equina decreased significantly under dynamic burdens during static compression. Two kinds of dynamic burdens introduced at the same time can cause more profound change than a single one.
ObjectiveTo observe the dynamic changes of plasma Clara cell secretory protein (CC16) in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD), and to explore its role in the occurrence and development of the disease and clinical significance.MethodsA total of 71 AECOPD patients were included in this study as observation group. All subjects completed the CAT questionnaire and were sampled 2 ml of venous blood on day 1 and day 7 after their admission. And the percentage of forced expiratory volume in the first second (FEV1%pred), percentage of forced vital capacity in the estimated value (FVC%pred), FEV1/FVC ratio, arterial partial pressure of carbon dioxide (PaCO2), white blood cell count (WBC), the proportion of neutrophils (NEUT%), C-reactive protein (CRP), procalcitonin (PCT) and the length of stay of subjects were recorded. Another 20 healthy adults were enrolled as the control group. Each subject of the control group was sampled 2 ml of venous blood. The plasma CC16 levels of the two groups were tested and compared, and analyzed its correlation with CAT score and length of stay.ResultsThe plasma CC16 level of AECOPD patients was significantly lower than that of the control group, lung function was significantly lower than that of the healthy control group, WBC and NEUT% were significantly higher than that of the healthy control group, and the difference was statistically significant (P<0.05). Compared with day 1 after admission, the plasma CC16 level, CAT score, PaCO2, WBC, NEUT%, CRP, PCT of AECOPD patients on day 7 were significantly decreased, with statistically significant differences (P<0.05). The plasma CC16 level of AECOPD patients was negatively correlated with their CAT score (r=–0.704, P<0.001), and also was negatively correlated with the length of stay (r=–0.351, P=0.003).ConclusionsCC16 is involved in the development and progression of AECOPD and closely related to the severity and prognosis of the disease. Its dynamic changes can predict the condition changes and evaluate the clinical treatment effect of patients with AECOPD. Combined with common clinical indicators, CC16 can shorten the length of stay of patients.
Objective To evaluate the influence on the estimation of respiratory mechanics with dynamic signal analysis approach during noninvasive positive pressure ventilation (NPPV) under different inspiratory effort conditions. Methods The Respironics V60 ventilator was connected to a ASL5000 lung simulator, which simulate lung mechanics in healthy adults with body weight from 65 to 70 kg, and patients with chronic obstructive pulmonary disease (COPD) and acute respiratory distress (ARDS). Each lung models was subjected to 4 different muscle pressures (Pmus): 0, 5.0, 10.0, and 15.0 cm H2O. Inspiratory pressure support level was adjusted to maintain tidal volume (VT) achieving 7.0 mL/kg outputted by ventilator respectively. Positive end expiratory pressure was set at 5.0 cm H2O and back-up rate was 10 beats per minute. Measurements were conducted at system leaks with 25 to 28 L/min. The respiratory system compliance (Crs), inspiratory and expiratory resistance (Rinsp and Rexp) were estimated by special equations, which was derived from the exhaled VT, flow rate and airway pressure. Results The driving pressure (DP) was decreased with Pmus increasing, and was 1.0 cm H2O after Pmus exceeding 10.0 cm H2O and the VT was larger than 7.0 mL/kg in normal adult model. The estimated value of Crs was affected by the changes of Pmus in all three lung models. The significant underestimation of Raw and the overestimation of Crs were observed when Pmus level exceed 10.0 cm H2O. The measured errors of Crs and Rexp were within 10% in COPD and ARDS model when Pmus was at 5.0 cm H2O. The underestimation of Rinsp was always existed in all Pmus level (P<0.01). Conclusions Using dynamic signal analysis approach, the real-time estimation of respiratory mechanics (Crs and Raw) is no need to interrupt the spontaneous breathing during NPPV. Excessive effort will increase the patient’s inspiratory workload, which is not benefit to accurate estimation of respiratory mechanics.
Objective To compare the curative effect of dynamic hi p screw (DHS) combined with anti-rotation screw and cannulated screw in treating patients with Pauwels type II or III femoral neck fracture and to provide the basis for the choice of surgical procedure. Methods Between March 2008 and September 2009, 51 patients with fresh Pauwels type II or III femoral neck fracture were treated with DHS combined with anti-rotation screw (DHS group) and three cannulated screws (cannulated screw group). The DHS group included 23 patients, 13 males and 10 females, aging 27-59 years (mean, 43.2 years); fracture was caused by fall ing in 1 case, by traffic accident in 17, by fall ing from height in 5 with a mean time of 27 hoursfrom injury to hospital ization (range, 12-70 hours); and 23 fractures included 9 Pauwels type II and 14 Pauwels type III femoral neck fracture. The cannulated screw group included 28 patients, 12 males and 16 females, aging 20-60 years (mean, 40.7 years); fracture was caused by fall ing in 1 case, by traffic accident in 22, by fall ing from height in 5 with a mean time of 25 hours from injury to hospital ization (range, 9-38 hours); and 28 fractures included 12 Pauwels type II and 16 Pauwels type III femoral neck fracture. There was no significant difference in the basel ine characteristics between 2 groups (P gt; 0.05). Results The incision heal ing of both groups by first intention was achieved. There were significant differences in operation time, incision size, operation blood loss, the cases of blood transfusion, the amount of blood transfusion, C reaction protein level on the 2nd postoperative day, and hospital ization days between 2 groups (P lt; 0.05). In DHS group, anatomic reduction was observed in 20 cases (86.96%) and satisfactory reduction in 3 cases (13.04%), while in cannulated screw group, anatomic reduction was observed in 25 cases (89.29%) and satisfactory reduction in 3 cases (10.71%) ; there was no significant difference (χ2=0.660, P=1.000). The patients were followed up 12-30 months with an average of 14.8 months. There was no significant difference (P gt; 0.05) in the rate of nonunion (10.71% vs. 0), the implant failure (3.57% vs. 0), and avascular necrosis of the femoral head (10.71% vs. 0) between the DHS group and the cannulated screw group. The union time was (94.5 ± 2.0) days in the DHS group and (106.0 ± 33.5) days in the cannulated screw group, showing no significant difference (t=—1.641, P=0.107). The re-opereation rates and the overall success rates were 25% and 75% in the cannulated group and were 0 and 100% in the DHS group, showing significant differences (χ2=6.650, P=0.012). At last follow-up, there was no significant difference in Harris hip score and visualanalogue scale (VAS) score between DHS group and cannulated screw group (P gt; 0.05). Conclusion The optimal treatment of young adults Pauwels type II or III femoral neck fracture is DHS combined with anti-rotation screw with an high overall success and less compl ications.
ObjectiveTo investigate the correlation between intima-media thickness (IMT) of carotid artery in color ultrasonography and the heart rate variability. MethodsA retrospective analysis was performed in 64 patients from West China Hospital of Sichuan University between March and May 2013. Carotid intima-media thickness was measured with color ultrasonography and dynamic electrocardiogram, and the heart rate variability was assayed at the same time. ResultsIMT in the cardiovascular disease group, combination group, coronary heart disease group and hypertension group was significantly thicker than the control group (P<0.05). The differences of SDNN and SDANN were statistically significant (P<0.05) between the combination group and the control group. There were 23 cases with IMT ≥ 1.0 mm in the cardiovascular disease group including 8 cases in the combination group, 10 cases in the coronary heart disease group and 5 cases in the hypertension group. IMT in those groups were all significantly higher than that in the control group with only 2 cases having IMT ≥ 1.0 mm (P<0.05). There were 18 cases with SDNN<100 ms in the cardiovascular disease group including 7 cases in the combination group, 6 cases in the coronary heart disease group and 5 cases in the hypertension group, but there was no statistically significant difference compared with that in the control group with only 11 cases (P>0.05). Negative correlation was found between IMT and SDNN, SDANN in the cardiovascular diseases group (r=-0.574, -0.544; P<0.01) and negative correlation was found between IMT and SDANN in the control group (r=-0.392, P<0.05). ConclusionThe carotid artery lesions and autonomic nerve especially sympathetic nerve dysfunction are obvious in patients with cardiovascular diseases and there is a negative correlation between them.
Objective To study the effectiveness of anterolateral C-shaped approach in the treatment of intertrochanteric fracture of the femur in elderly patient by comparing with traditional anterolateral approach. Methods Between April 2010 and November 2011, 66 patients with intertrochanteric fracture of the femur were analyzed retrospectively. Of 66 patients, 37 underwent improved anterolateral C-shaped approach combined with fixation of dynamic hip screw (DHS) (improved group), and 29 underwent traditional anterolateral approach combined with fixation of DHS (conventional group). There was no significant difference in gender, age, injury cause, side, disease duration, fracture type, and complication between 2 groups (P gt; 0.05). The operation time, intraoperative blood loss, postoperative drainage volume, and hospitalization time were recorded; and X-ray films were taken to observe the fracture healing. The hip function was evaluated according to self-established criterion. Results The operation was successfully completed in all patients, and primary healing of incision was achieved. All patients were followed up 12-24 months (mean, 17.8 months). Bone union was achieved in both groups; the fracture healing time was 3-6 months (mean, 4.8 months). No loosening or breaking of internal fixation was observed during follow-up period. The operation time and postoperative drainage volume of improved group were significantly less than those of conventional group (P lt; 0.05); no significant difference was found in intraoperative blood loss and hospitalization days between 2 groups (P gt; 0.05). According to self-established criterion, improved group was significantly better than conventional group in recovery of hip joint motion and function at 6 and 12 months after operation (P lt; 0.05). Conclusion Anterolateral C-shaped approach combined with DHS could minimize muscle injury and scar formation, which is beneficial to surgical exposure and early postoperative rehabilitation.
In recent years, it has become a new direction in the field of neuroscience to explore the mode characteristics, functional significance and interaction mechanism of resting spontaneous electroencephalography (EEG) and task-evoked EEG. This paper introduced the basic characteristics of spontaneous EEG and task-evoked EEG, and summarized the core role of spontaneous EEG in shaping the adaptability of the nervous system. It focused on how the spontaneous EEG interacted with the task-evoked EEG in the process of task processing, and emphasized that the spontaneous EEG could significantly affect the performance of tasks such as perception, cognition and movement by regulating neural activities and predicting external stimuli. These studies provide an important theoretical basis for in-depth understanding of the principle and mechanism of brain information processing in resting and task states, and point out the direction for further exploring the complex relationship between them in the future.