Objective To study the relationship between on-line correction and stiffness of the upper limb during human movements, so as to improve the measurement accuracy of stiffness and to assess the on-line correction capability. Methods Five kinds of upper limb goal-directed movements in a horizontal plane were designed. The stiffness values at 5 different positions, i.e. in the early period, early to mid period, mid period, mid to late period and late period separately during the movements with sudden perturbation were measured to investigate the regular pattern of human hand stiffness influenced by such on-line correction, as well as the relationship between the movement accuracy and hand stiffness. Results The stiffness was always varying during the movements, and the variation of the stiffness would influence the movement error. On-line correction during the movements could induce an increase in the value of stiffness amplitude, especially at the position in late period of the movement. However, no significant linkage was found between the change of stiffness and the occurrence time or content of on-line correction. Conclusions On-line correction plays an important role in goal-directed movements. Considering that on-line correction may cause a change in the amplitude of the stiffness, the on-line correction function of patients can be more accurately assessed by measuring stiffness value in specific experiments, combined with other medical diagnosis methods in clinic.

OBJECTIVETo report the treatment of a case of severe Crouzon's syndrome using monobloc distraction osteogenesis and cranial vault remodeling.

METHODSThrough intra-and extra-cranial approach, monobloc osteotomy was performed and external distractor was placed. Distraction began on the 7th postoperative day at a rate of 1 mm a day, two times a day. The distractor removed after consolidation for 4 months.

RESULTSThe distraction distance attained 20 mm. The exophthalmos and cross bite were corrected completely. The severe obstructive apnea improved markedly.

CONCLUSIONSMonbloc distraction osteogenesis and cranial vault remodeling are effective and safe procedure for Crouzon's syndrome.

Child ; Craniofacial Dysostosis ; surgery ; Female ; Humans ; Osteogenesis, Distraction ; methods ; Osteotomy ; Skull ; surgery

Objective:To explore the effect of real-time visual trajectory feedback on the motor learning ability of healthy volunteers during upper limb circle-drawing movements by using rehabilitation robots. Methods:From July to September, 2018, 24 right-handed healthy volunteers were divided into two groups according to the baseline level of motor ability, one group received three kinds of feedbacks including visual, result and real-time trajectory feedbacks (V+KP+KR group), and the other group only received two kinds of feedbacks including visual and performance (V+KR group). Both groups were trained in clockwise circle drawing task under different conditions for five sessions, 20 times per session, and then underwent one session of maintenance test after three days. The motor learning processes of two groups were evaluated and analyzed by two parameters including roundness score and completion time. Results:By using two-factor repeated measures variance analysis, it was found that there were intergroup and intragroup interactions (F = 6.029, P < 0.001). The intergroup individual effects showed that except for the fifth training section (F = 8.775, P = 0.658), the values of roundness score in other sessions were higher in V+KP+KR group than in V+KR group (F > 13.126, P < 0.001). The intragroup individual effects showed that there were significant differences among sessions in both groups (F > 12.465, P < 0.001). For completion time, there was no intergroup and intragroup interactions (F = 1.606, P = 0.228), the intergroup main effect was not significant (F = 0.55, P = 0.477), and the intragroup main effect was significant (F = 3.95, P = 0.031). Conclusion:Real-time trajectory feedback can help volunteers quickly understand the essentials of motor tasks at the early stage of motor learning, thus helping them to improve the fast learning ability of new tasks, but the improvement effect on motor learning during middle and late stages is not obvious. The dependence of volunteers on real-time trajectory feedback gradually decreases in the middle and later stages of motor learning, and they might rely on proprioception to complete tasks.

High expression of Bcl-2 is associated with the development of pancreatic cancer, and downregulation of Bcl-2 is an effective approach for the treatment of pancreatic malignancy. In the present study exosomes were isolated from the cultured medium of human embryonic kidney cells (HEK293) by ultracentrifugation and exosome-coated Bcl-2 siRNA (exosiBcl-2) was synthesized using electroporation. The results showed that the particle size of exosiBcl-2 was 67.3 ± 9.7 nm and the morphology of exosomes displayed a concave ring structure as determined by transmission electron microscopy (TEM). Western blot analysis indicated that exosomal proteins including CD9, CD81, CD63 and TSG101 were highly expressed. Confocal microscopy revealed that exosiBcl-2 was widely distributed in Miapaca-2 cells, and the transfection efficiency of exosiBcl-2 in Miapaca-2 was 77.2% as determined by flow cytometry. Treatment with exosiBcl-2 at a concentration of 100 nmol·L^-1 resulted in an inhibitory effect on the growth of Miapaca-2 cells with an inhibition rate of 63%. ExosiBcl-2 treatment can downregulate Bcl-2 and upregulate Bax protein. This study provides evidence that exosiBcl-2 is able to inhibit the growth of pancreatic cancer cells and the nanoparticles have potential to be developed as a novel anticancer agent.

Objective:To solve the issue regarding a low correlation between visual and haptic feedback provided by the current upper-limb rehabilitation training system, this study was implemented based on the end-effector based upper-limb rehabilitation robot developed in the lab. A novel visual and haptic feedback fusion technology based on force tracking was investigated and its effect on upper-limb training was also studied. Methods:Based on the force model constructed in a virtual environment, two types of haptic feedbacks correlated to the visual feedback were designed, including the repulsive force when two objects getting close and the friction force when the object moving above medium surfaces. The haptic feedback constructed in the virtual environment was delivered to the trainees by using force tracking based on robot controlling algorithm. Eight health subjects were recruited and trained with and without feedback fusion. In the training process, the actual and expected haptic feedbacks as well as the surface electromyography (EMG) signals from anterior deltoid, posterior deltoid, biceps, and triceps were collected. The root means square error (RMSE) between the actual and expected haptic feedback was calculated under the feedback fusion training mode to characterize the force tracking-based multi-sensory feedback fusion technology. The integrated EMG values (iEMG) and EMG amplitudes per unit time (EMG/T) under two training modes were measured to explore the effect of feedback fusion technology on the upper-limb motor training. Results:Under feedback fusion training mode, the RMSE between actual and expected haptic feedback was (0.757±0.171) N. The values of iEMG from four muscles were significantly higher (|t| > 7.965, P < 0.001), and the values of EMG/T from the biceps, triceps and anterior deltoid were significantly larger under feedback fusion training mode than under the training mode without feedback fusion. Conclusion:The proposed upper-limb rehabilitation robot training system could accurately transmit the haptic feedback constructed under the virtual environment to the trainees. This system could increase the stimulation to trainees' peripheral nervous function through visual and haptic feedback fusion as well as increase the trainees' training effort. The advantages of force tracking-based visual and haptic feedback fusion technology are to freely construct the force model under the virtual environment and the haptic feedback mode is not constrained by the spatial position. Moreover, two or more types of force models can be superimposed in the same spatial position by using this technology that could improve the matching effect between haptic feedback and visual feedback under a virtual environment. The trainees' motor rehabilitation interest could be stimulated and the experience feeling of human-robot interaction could also be enhanced.

Objective: To examine the safety and effectiveness of a new stent graft system for endovascular repair of abdominal aortic aneurysm(AAA). Methods: This is a prospective,multi-center,single-arm clinical trial. The patients with AAA treated with a new stent graft system were enrolled at 21 centers from September 2018 to September 2019 in China. Follow-up was performed before discharge, and at 30, 180, 360 days after operation, respectively. The primary safety endpoint was the incidence of major adverse events(MAE) within 30 days. The primary efficacy endpoint was the success rate of AAA treatment at 360 days. Secondary safety endpoints were the incidence of perioperative access complications and acute lower limb ischemia,all-cause mortality, AAA related mortality and incidence of serious adverse events (SAE) at 180 and 360 days. Secondary efficacy endpoints were the incidence of type Ⅰ or Ⅲ endoleak,stent displacement,and conversion to open surgery or re-intervention at 180 and 360 days. Results: One hundred and fifty-six patients were enrolled,including 137 males and 19 females. The age was (68.9±6.9) years (range:48.2 to 84.6 years).Maximum aneurysm diameter was (50.8±11.2) mm (range:25.0 to 85.0 mm),diameter of proximal landing zone was (21.2±2.5) mm (range:17.0 to 29.5 mm),and length of proximal landing zone was (31.4±13.0) mm (range:11.0 to 75.0 mm).The incidence of MAE was 1.3% (2/156) at 30 days,both were all-cause death cases. The success rate of AAA treatment was 88.5% (138/156) at 360 days. No perioperative access complication and acute lower limb ischemia occurred. All-cause mortality was 2.0% (3/154) at 180 days and 2.6% (4/153) at 360 days,and there was no AAA related death. The incidence of SAE was 23.0%(35/152) at 180 days and 30.5%(46/151) at 360 days, and no device-related SAE occurred. The incidence of type Ⅰor Ⅲ endoleak was 3.4% (5/147) at 180 days and 3.5% (5/144) at 360 days. Conclusion: The new stent graft system is easy to operate,and early-term safety and effectiveness results are expected.
Humans ; Middle Aged ; Aged ; Aged, 80 and over ; Prospective Studies ; China ; Ischemia ; Aortic Aneurysm, Abdominal/surgery*