BAcKGROUND:In recent years,the pedicle screws fixation technique,which is used in fixation for atlantoaxial instability associated with trauma,severe degeneration and tumorectomy,has been developed.However,this kind of technique easily causes several complications,including malpositional screws,vascular injuries,and even vertebral artery injury.Based on the biomechanical characteristics of memory alloy and determination of atlantoaxial data,a neotype shape memory alloy cervical hook was designed to treat atlantoaxial instability.OBJECTIVE:To investigate the biomechanieal characteristics of the neotype shape memory alloy cervical hook for atlantoaxial instability.DESIGN,TIME AND SETTING:Repeated measurement analysis of variance test was performed in the Laboratory of Clinical Anatomy and Medical Biomechanics,Southern Medical University between March and April 2008.MATERIALS:Eight fresh adult craniocervical specimens(C0-C4)were provided by Department of Clinical Anatomy,Southern Medical University.Atlantoaxial neotype shape memory alloy cervical hook(50.8%-51.8%nickel and the remaining part was titanium)was fabricated by Shanghai Xinchang Memory Alloy Co.,Ltd.METHODS:The included eight C0-C4 specimens were used to test three-dimension ranges of motion(ROM)by fixation and neotype shape memory alloy cervical hook fixation.Then,the positions of spine varying from no loading to the maximum loading status were scanned and analyzed using image processing software to determine the three-dimensional ROM under different statuses.MAIN OUTCOME MEASURES:Three-dimensional ROM of tested specimens.RESULTS:Neotype shape memory alloy cervical hook fixation and Germany AESCULAP SSE hanger fixation had similar flexion-extension range of motion(P=0.595).Lateral bending three-dimensional ROM was greater in the neotype shape memory alloy cervical hook fixation group than in the Germany AESCULAP AAE hanger fixation(P< 0.05).The rotatory three-dimensional ROM was smaller in the neotype shape memory alloy cervical hook fixation group than in the Germany AESCULAP AAE hanger fixation(P<0.05).CONCLUSION:Neotype shape memory alloy cervical hook fixation had comparative post-surgery immediate stability with the Germany AESCULAP AAE hanger fixation.Neotype shape memory alloy cervical hook fixation produced a little worse biomechanical lateral bending stability and a little better biomechanical rotatory stability than Germany AESCULAP AAE hanger fixation.

BACKGROUND: Biodegradable internal fixation devices have been used in clinics. However, they can only be used for internal fixation of non weight-bearing bones. A new kind of biodegradable internal fixation device with high initial strength and slow early degradation, which can be used for weight-bearing bones, is required.OBJECTIVE: To test the initial strength and observe the degradation of human hair polylactic acid (HHPLA) composite rods.DESIGN: Repeated measurement designSETTING: Center of Orthopaedic Department, Zhujiang Hospital, Southern Medical University; Department of Human Anatomy of Southern Medical UniversityMATERIALS: The experiment was conducted in the Southern Medical University between September 2002 and October 2003. Totally 54 adult SD rats were recruited.METHODS: ①The shear strength, the bending strength and the bending modulus of 20 HHPLA composite rods were tested with the biomechanical testing system (MTS-858 Mini Bionix) to investigate the initial nechanical feature of HHPLA composite rods. ②A total of 108 samples of HHPLA composite rods, which were developed for internal fixation of fracture, were randomly implanted in bilateral dorsal subcutaneous tissue of 54 SD rats and taken out at weeks 1, 2, 4, 8, 12, 16, 20, 24 and 28 (6 rats at each time point). The weight losses were measured to understand the degradation of HHPLA composite rods in SD rats.MAIN OUTCOME MEASURES: ①Mechanical strength of HHPLA composite rods. ②Degradation in vivo of HHPLA composite rods.RESULTS: Totally 54 rats entered the result analysis. ①HHPLA composite rods has good initial mechanical strength. Its shear strength of the HHPLA rod was 241 MPa, bending strength was 358 MPa, and the bending modulus was 13 GPa. ②HHPLA was fairly degradable in SD rats.Degradation was slower in the earlier period than that in the later period.CONCLUSION: HHPLA composite rods have some fairly good characteristics of initial mechanical strength and degradation in vivo.

Morulaes and blastocysts obtained from Guanzhong dairy goats 6-7 days after mating were treated with whole embryo cultivaton, enzymatic digestion and immunosurgery separately. The goat embryonic stem cells (ESC) were isolated and cultured on a feeder layer of mitomycin-inactivated mouse embryo fibroblasts (MEF). The characteristics of goat ESCs were analyzed by immunohistochemisty, RT-PCR and inducing differentiation in vitro. The results indicated that the embryos were easier to attach the culture dish and form primary colonies with whole embryo method. There were colonies that maintained undifferentiated for 18 passages. The ESCs expressed the protein of Nanog, Oct4 and SSEA-3, whereas the protein of SSEA-4 was absent and the protein of SSEA-1 was weakly expressed. In addition, the genes of Nanog, Oct4, TERT and CD117 were expressed in goat ESCs. The cells also could differentiate to myocardial cells when induced in vitro by DMSO. These results suggest that the goat ESCs have characteristics of ESCs.
Animals ; Blastocyst ; cytology ; Cell Differentiation ; physiology ; Cell Separation ; methods ; Cells, Cultured ; Embryo Culture Techniques ; Embryo, Mammalian ; cytology ; Embryonic Stem Cells ; cytology ; metabolism ; Female ; Goats ; Male ; Mice ; Myocytes, Cardiac ; cytology ; Rabbits

To optimize program of bovine somatic nuclear transfer, we used two different enucleation procedures (by Spindle-view system & Hoechst 33342 staining), two different procedures to introduce donor nuclei (by ooplasm microinjection & electrofusion), and three different group electrofusion parameters (group 1: 1.9 kV/cm, 10 micros, two; group 2: 1.5 kV/cm, 25 micros, two; group 3: 0.6 kV/cm, 100 micros, one) to reconstruct bovine cloned embryos. The cleavation rates and blastocyst development rates of cloned embryos were used to assess the efficiency of different operational procedure. Finally, the best combination of operational procedure, that the spindle-viewer system was used for oocytes enucleating, and donor cell was electrofused into ooplasm by electrical pulse (1.9 kV/cm, 10 micros, two) to reconstruct bovine cloned embryos. Then the excellent blastocysts were transferred to fosters for producing cloned cattle 80 high-quality cloned blastocysts were transferred into 33 fosters, two cloned calves were produced. According to the results, the optimized program could be used to produce cloned cattle.
Animals ; Cattle ; Cell Nucleus ; physiology ; Cloning, Organism ; veterinary ; Embryo Transfer ; methods ; Embryo, Mammalian ; cytology ; physiology ; Female ; Microinjections ; Nuclear Transfer Techniques ; veterinary ; Oocytes ; cytology ; physiology

The integrity and transparency of cornea plays a key role in vision. Limbal Stem Cells (LSCs) are precursors of cornea, which are responsible for self-renewal and replenishing corneal epithelium. Though it is successful to cell replacement therapy for impairing ocular surface by Limbal Stem Cell Transplantation (LSCT), the mechanism of renew is unclear after LSCT. To real time follow-up the migration and differentiation of corneal transplanted epithelial cells after transplanting, we transfected venus (a fluorescent protein gene) into goat LSCs, selected with G418 and established a stable transfected cell line, named GLSC-V. These cells showed green fluorescence, and which could maintain for at least 3 months. GLSC-V also were positive for anti-P63 and anti-Integrinbeta1 antibody by immunofluorescent staining. We founded neither GLSC-V nor GLSCs expressed keratin3 (k3) and keratinl2 (k12). However, GLSC-V had higher levels in expression of p63, pcna and venus compared with GLSCs. Further, we cultivated the cells on denude amniotic membrane to construct tissue engineered fluorescent corneal epithelial sheets. Histology and HE staining showed that the constructed fluorescent corneal epithelial sheets consisted of 5-6 layers of epithelium. Only the lowest basal cells of fluorescent corneal epithelial sheets expressed P63 analyzed by immunofluorescence, but not superficial epithelial cells. These results showed that our constructed fluorescent corneal epithelial sheets were similar to the normal corneal epithelium in structure and morphology. This demonstrated that they could be transplanted for patents with corneal impair, also may provide a foundation for the study on the mechanisms of corneal epithelial cell regeneration after LSCT.
Animals ; Cell Culture Techniques ; methods ; Cell Line ; cytology ; Epithelium, Corneal ; cytology ; metabolism ; Fluorescent Antibody Technique, Indirect ; Goats ; Limbus Corneae ; cytology ; Stem Cell Transplantation ; Stem Cells ; cytology

Brain-computer interface (BCI) is a revolutionizing human-computer Interaction, which is developing towards the direction of intelligent brain-computer interaction and brain-computer intelligent integration. However, the practical application of BCI is facing great challenges. The maturity of BCI technology has not yet reached the needs of users. The traditional design method of BCI needs to be improved. It is necessary to pay attention to BCI human factors engineering, which plays an important role in narrowing the gap between research and practical application, but it has not attracted enough attention and has not been specifically discussed in depth. Aiming at BCI human factors engineering, this article expounds the design requirements (from users), design ideas, objectives and methods, as well as evaluation indexes of BCI with the human-centred-design. BCI human factors engineering is expected to make BCI system design under different use conditions more in line with human characteristics, abilities and needs, improve the user satisfaction of BCI system, enhance the user experience of BCI system, improve the intelligence of BCI, and make BCI move towards practical application.
Brain ; Brain-Computer Interfaces ; Electroencephalography ; Ergonomics ; Humans ; User-Computer Interface

Brain-computer interface (BCI) is a revolutionary human-computer interaction technology, which includes both BCI that can output instructions directly from the brain to external devices or machines without relying on the peripheral nerve and muscle system, and BCI that bypasses the peripheral nerve and muscle system and inputs electrical, magnetic, acoustic and optical stimuli or neural feedback directly to the brain from external devices or machines. With the development of BCI technology, it has potential application not only in medical field, but also in non-medical fields, such as education, military, finance, entertainment, smart home and so on. At present, there is little literature on the relevant application of BCI technology, the current situation of BCI industrialization at home and abroad and its commercial value. Therefore, this paper expounds and discusses the above contents, which are expected to provide valuable information for the public and organizations, BCI researchers, BCI industry translators and salespeople, and improve the cognitive level of BCI technology, further promote the application and industrial transformation of BCI technology and enhance the commercial value of BCI, so as to serve mankind better.
Brain/physiology* ; Brain-Computer Interfaces ; Electroencephalography ; Humans ; Technology ; User-Computer Interface

Speech expression is an important high-level cognitive behavior of human beings. The realization of this behavior is closely related to human brain activity. Both true speech expression and speech imagination can activate part of the same brain area. Therefore, speech imagery becomes a new paradigm of brain-computer interaction. Brain-computer interface (BCI) based on speech imagery has the advantages of spontaneous generation, no training, and friendliness to subjects, so it has attracted the attention of many scholars. However, this interactive technology is not mature in the design of experimental paradigms and the choice of imagination materials, and there are many issues that need to be discussed urgently. Therefore, in response to these problems, this article first expounds the neural mechanism of speech imagery. Then, by reviewing the previous BCI research of speech imagery, the mainstream methods and core technologies of experimental paradigm, imagination materials, data processing and so on are systematically analyzed. Finally, the key problems and main challenges that restrict the development of this type of BCI are discussed. And the future development and application perspective of the speech imaginary BCI system are prospected.
Brain ; Computers ; Humans ; Imagery, Psychotherapy ; Speech ; Technology

Motor imagery (MI) is an important paradigm of driving brain computer interface (BCI). However, MI is not easy to control or acquire, and the performance of MI-BCI depends heavily on the performance of the subjects' MI. Therefore, the correct execution of MI mental activities, ability evaluation and improvement methods play important and even critical roles in the improvement and application of MI-BCI system's performance. However, in the research and development of MI-BCI, the existing researches mainly focus on the decoding algorithm of MI, but do not pay enough attention to the above three aspects of MI mental activities. In this paper, these problems of MI-BCI are discussed in detail, and it is pointed out that the subjects tend to use visual motor imagery as kinesthetic motor imagery. In the future, we need to develop some objective, quantitatively visualized MI ability evaluation methods, and develop some effective and less time-consumption training methods to improve MI ability. It is also necessary to solve the differences and commonness of MI problems between and within individuals and MI-BCI illiteracy to a certain extent.
Algorithms ; Brain-Computer Interfaces ; Electroencephalography ; Humans ; Imagery, Psychotherapy ; Imagination