Assistive technology has been one of key words in the field of special education. It will also be new trend of special educational development. In the article, the authors firstly introduced the definition of assistive technology device and assistive technology service and discussed the relationship between assistive technology and educational technology, and special educational changes in technology and idea because of the use of assistive technology, at last, some suggestions to enhance the use of assistive technology were put forward.

Objective To establish a database for models of teeth, which could provide a new technology for personal identification based upon teeth and bite mark for forensic medical practice. Method The (X, Y) digital coordinates were established based up on materials concerning shape and arrangement of the teeth by analyzing samples of 400 models of teeth. The position of every tooth's key point corresponding to the origin was obtained, thus, the characters of tooth and dental arch could be calculated rapidly according to Borland C ++ 5.0 computer language under DOS system. Results The models of teeth could be identified automatically. Among the correlative precision indexes, the length was 1.3mm, the angle was 3?. It seems reasonable to select 12-14 teeth points for studying, which needed about 5-7 complete tooth marks. Conclusion This method is one of the bases in studying personal identification relating to tooth and bite mark.

Objective To discuss the condition in which ricochet bullet wound is formed, study its ballistic characters and ability to damage in the body, and establish features for the diagnosis of ricochet bullet wound. Method We shot four Yorkshire pigs by selecting No.54 pistol (made in China) and No.56 semiautomatic rifle with No.51 pistol bullet and No.56 rifle bullet, using quern stone as ricocheting target, copied 12 cases of ricochet bullet wound models and observed the characters of entrance wound, wound cavity and cartridge point. Results The formation of ricochet bullet lies with the properties of the target, the shape and velocity of the bullet, angle of incidence and angle of ricochet; the angle of ricochet formed by sharp bullet with high velocity is smaller than the angle by the round bullet with low velocity under the same circumstance; the wound does not produce an evident temporary cavity; six features for the diagnosis were established according to experimented results. Conclusion The correct diagnosis of ricochet bullet wound is of practical value to judging direction and distance of shot, trajectory reconstruction, analysing purpose of shot and evaluation of injury degree.

Regarding the fact that there is a huge gap between higher education of assistive technology in China and the social need, the authors discussed about the necessity of developing China's higher education of assistive technology, by discussing about the fact that assistive technology becoming an independent subject, society's need for leaders and designers in the field of assistive technology, the need to develop assistive technology theories and knowledge, the important meaning of developing higher education of special education to support the independent living of persons with disability and opening potential market, the successful example of America's assistive technology and higher education of it being in the leading place.

Objective To investigate the outcome of a new designed extramedullary femoral alignment system and to compare with conventional intramedullary system in clinical results.Methods Twenty consecutive patients (3 males and 17females with an average age of 70.1 (range,52-82 years old) with osteoarthritis (OA) or rheumatoid arthritis (RA) who were treated with the extramedullary method between January 2015 to August 2015 and 20 consecutive patients (5 males and 15 females with an average age of 65.9 (range,52-87 years old) with OA or RA treated with conventional intramedullary method between April 2015 to September 2015 were studied.In extramedullary group,CT scan was used to evaluate the relation between the hip (femoral head) center and anterior superior iliac spine preoperatively.During the total knee arthroplasty,the hip joint center was defined according to the anterior superior iliac spine (ASIS).Knee joint center was defined as the center of the line connecting medial and lateral epicondyle.The terminal femoral bone cut plane was defined as the line between femoral and knee center.In intramedullary group,the traditional intramedullary method was adopted.The coronal and sagittal alignment,blood loss and drainage at one week postoperatively and the range of motion at one week,6 weeks and 3 months were evaluated.Results There was no significant difference in age,hip-knee-ankle (HKA) angle,the Hospital for Special Surgery (HSS) Knee Score,BMI,operation time within the two groups.Blood loss and drainage in extramedullary group (121 ±64 ml and 181±149 ml) was significantly less than that in intramedullary group (177±47 ml and 292±156 ml).There was no significant difference in coronal alignment of the femoral prosthesis within the two groups (89.8°±2.1° v.s.89.8°±2.2°,P＞0.05).However,the two groups had significant difference in sagittal alignment (-0.8°±2.2° v.s.2.5°±2.1 °,P＜0.05).The alignment of extramedullary group had much more tendency in flexion degree.No difference was found in range of motion at 1 week,6 weeks and 3 months postoperatively (103.8°±7.8° v.s.102.5°±7.2°,108.5°±8.0° v.s.108.3°±7.4°,117.0°±7.1° v.s.114.5°±8.1°,P＞0.05).Conclusion The present designed extramedullary system is practical in total knee arthroplasty and has more accuracy in sagittal plane.The patients treated with extramedullary system have less blood loss and drainage and have similar range of motion in early stage after operation when compared with the intramedullary method.

BACKGROUND:Study confirms that bone morphogenetic protein can induce osteogenesis;however the ultrastructure of periosteal cells induced by bone morphogenetic protein-7 remains poorly reported.
OBJECTIVE:To study the bioactivity and ultrastructure of periosteal cells induced by bone morphogenetic protein-7 in vitro.
METHODS:The primary periosteal cells isolated from adult tibial bone were in vitro cultured, and then divided into experimental group and control group. In the experimental group, cells were cultured with bone morphogenetic protein-7 and culture adjuvant;while cells in the control group were only cultured with the adjuvant. Three samples in each group were tested at 5, 10, 15 days, respectively. The general structure of cultured cells was observed using von Kossa staining, and the ultrastructure was observed under transmission electron microscopy.
RESULTS AND CONCLUSION:The periosteal cells in the two groups grew wel in vitro, showing uniform morphology. Early cells were spindle-shaped, with strong three-dimensional sense and ful transparency;mitotic cells were short columnar or cubic shaped, there were a lot of rough endoplasmic reticulum and Golgi complex in osteoblasts under electron microscope. Later stage of cells developed from long fusiform into wide shuttle and irregular shape, there were a large number of matrix vesicles within the cells under the electron microscope. The membrane coating, alkaline phosphatase and calcium-binding protein in the cytoplasm, as wel as calcium crystals were found. The osteogenesis basement and lateral sides appeared projections, which were connected with adjacent bone cells. Induction of bone morphogenetic protein-7 in vitro promotes the osteoblasts proliferation, division and bone formation speed. The results suggest that bone morphogenetic protein-7 can significantly enhance the proliferation ability of osteoblasts in vitro.

Objective:To investigate the correlation and dose-response relationship of pulse pressure and pulse pressure index with metabolic syndrome in the elderly population.Methods:This was a cross-sectional study.A total of 114 212 subjects aged 65 years and over in Wujin District receiving health examination in 2019 were enrolled, including 40 388(35.4%)patients with metabolic syndrome.The survey contents included a questionnaire, physical examination and laboratory tests.Logistic regression and restricted cubic splines were used to analyze the correlation and dose-response relationship of pulse pressure and pulse pressure index with metabolic syndrome.Results:With increases in pulse pressure levels and pulse pressure index, the prevalence of metabolic syndrome and its components increased accordingly( P<0.01). After adjusting for confounding factors, the ORvalue of metabolic syndrome gradually increased along with increases in pulse pressure and pulse pressure index.Compared with the first quartile, pulse pressure and pulse pressure index in the second, third and fourth quartiles were correlated with metabolic syndrome(pulse pressure: OR=1.52, 95% CI: 1.47~1.58, OR=1.89, 95% CI: 1.82~1.96 and OR=2.15, 95% CI: 2.07~2.23, respectively; pulse pressure index: OR=1.22, 95% CI: 1.18~1.26, OR=1.36, 95% CI: 1.31~1.41 and OR=1.47, 95% CI: 1.42~1.53, respectively). Restricted cubic spline analysis showed that pulse pressure and pulse pressure index had non-linear dose-response relationships with metabolic syndrome( χ2=309.23 and 57.14, P<0.01). Conclusions:Pulse pressure and pulse pressure index are correlated and show non-linear dose-response relationships with metabolic syndrome and its components in the elderly.

Objective To investigation the condition,expectation and support of quality of life in adult with intellectual disability.MethodsA total of 394 adult with intellectual disability,their parents and friends in Beijing were involved in the study.Their qualities of life were evaluated.ResultsAbout quality of life,the adult with intellectual disability had significant more expectation than they had gained actually;their parents and friends had significant more expectation than themselves and staff of primary rehabilitation did.ConclusionIt is necessary to provide support to improve the quality of life of adult with intellectual disability.

Objective To investigate the different radioprotective effects of total flavonoids of Astragalus (TFA) on human normal mesenchymal stem cells(hMSCs) and hepatoma cells injured by 60 Coγ-ray radiation.Methods hMSCs and HepG-2 cells were cultured and randomly divided into TFA-treated and untreated groups.The cells of different groups were irradiated with 60 Co γ-rays at the dose of 6 Gy.MTT method was utilized to detect the survival rates of the hMSCs and HepG-2 cells pretreated or untreated with TFA before irradiation.Cell clone formation test was used to measure the cellular radiosensitivity.The apoptosis rates of different groups were determined by flow cytometer assay.The expression rates of the apoptosis-promoting proteins Fas and Bax and the apoptosis-inhibiting protein Bcl-2 were analyzed by Western blotting.Results MTT showed that the survival rates of hMSCs pretreated by TFA were 1.15-1.95 times higher than that of the pure irradiation group.On the contrary,the survival rates of the TFA pretreated HepG-2 cells were only 0.53-0.23 times that of the pure irradiation group.There was a good dose-effect relationship between the cell survival rate and the TFA concentration.Cell clone formation rate indicated that combined treatment of TFA and radiation inhibited the cell proliferation more effectively than single TFA or pure radiation.Flow cytometry showed that 6,24 and,48 h post-irradiation to 6 Gy,the apoptosis rates of the hMSCs were 23.3% ,11.2% ,and 2.9% ,respectively in the TFA pretreated group and were 29.3% ,24.9% ,and 13.6% in the pure radiation group.However,the apoptosis rates of the HepG-2 cells at 6,24,and 48 h post-irradiation to 6 Gy were 11.6% ,17.3% ,and 20.1% ,respectively in the TFA pretreated group and were 6.9% ,9.3% ,and 15.8% ,respectively in the direct radiation group.Western blotting showed that the expression levels of Fas and Bax proteins in the HepG-2 cells were significantly higher in the TFA pretreated group than in the pure radiation group.On the contrary,the expression level of the apoptosis inhibiting protein Bcl-2 was significantly lower in the TFA pretreated group than in the pure radiation group.Conclusions TFA has obvious effects of radiological protection on human hMSCs and has no effects of radiological protection but effects of apoptosis enhancement on hepatoma cells.The promotion of apoptosis of TFA on hepatoma cells is primarily through increasing the expression of apoptotic proteins such as Fas and Bax and reducing the expression of anti-apoptotic protein Bcl-2.