In recent years, along with the in-depth research of Y-STRs, a lot of new loci are found and applied in forensic medicines. To solve some questions, the International Society of Forensic Genetics have published two guidance and recommendations successively concerning the Y-STRs in 2001 and 2005, which clarify contents regarding the term, the nomenclature principle of loci and alleles and the population genetics et al of Y-STRs. This report mainly describes the nomenclature principle of loci and alleles of Y-STRs.

BACKGROUND:In terms of the histocompatibility, immune rejection and scar formation after repair, acel ular nerve al ograft is closer to autologous nerve cel s. At present, hyaluronic acid has been applied for autologous peripheral nerve repair;however, research on the nerve al ograft is rarely reported.
OBJECTIVE:To explore the effect of hyaluronic acid on the anastomotic scar in acel ular nerve al ograft repair of rat sciatic nerve defect.
METHODS:Thirty-six Sprague-Dawley rats were randomly divided into three groups (n=12 per group). The rat model of nerve defect of 10 mm was established by cutting the sciatic nerve of the left hind leg and then given nerve al ograft combined with the injection of hyaluronic acid at anastomosis (experimental group), only nerve al ograft (control group) and autologous nerve graft (nerve autograft group), respectively. Afterwards, the healing of the proximal anastomosis was observed and scar components were assessed.
RESULTS AND CONCLUSION:Gross observations showed that the rat skin and muscle fascia had no significant differences in healing among groups, while the surrounding tissue adhesion in the experimental group was milder than that in the control group (P<0.05). Masson staining found that col agen deposition in the epinerium could be observed in each group. In the experimental group, a smal amount of col agen fibers arranged orderly in the epineurium;in the control group numerous col agen fibers accumulated and arranged irregularly;in the nerve autograft group, sparse epineurial col agen fibers appeared in an order arrangement. The gray value of col agen type I in the experimental group was higher than that in the control group (P<0.05), while the gray value of col agen type III was lower than that in the control group (P<0.05). No significant differences were found in the sum gray values of col agen type I and III among groups (P>0.05). These findings indicate that in the peripheral nerve repair, hyaluronic acid abrogates the scar formation by increasing the deposition of col agen type III and reducing the deposition of col agen type I.

BACKGROUND:Prosthesis selection for total hip replacement is determined by geometrical matching with femoral medullary cavity of patients and the optimal biodynamics.It is of great significance for elevating outcomes of total hip replacement.OBJECTIVE:To evaluate the biomechanics of four groups of femoral stem prostheses matched with a femar and to get a stem whose mechanics distribution is similar to the normal femur.DESIGN:Controlled observation.SETTING:Department of Orthopaedics of Oriental Hospital Affiliated to Tongji University,Department of Orthopaedics of Changhai Hospital of Second Military Medical University of Chinese PLA,and Department of Mechanical and Power Engineering of Shanghai Jiao Tong University.MATERIALS:Experiments were performed at the Laboratory of Life Quality and Machinery Engineering of Department of Mechanical and Power Engineering of Shanghai Jiao Tong University from December 2004 to October 2005.A male volunteer aged 40 years with the normal proximal ferout(175 cm height and 78 kg weight),free from hip disease,were selected.X-ray image of the eutopic femar was shot and wrote into memory in the format of DICOM.The volunteer signed an infonned consent.The experiment was approved by Hospital Ethical Committee.No.Ⅰ prosthesis,Zimmer versys Fiber Metal Taperl 1#,No.Ⅱ prosthesis,Plus APL 2#,No.Ⅲ prosthesis,Welink Ribbed system cementless01#,and No.Ⅳprosthesis,Lima F2L 1# were used in this study.METHODS:The ezDICOM software was used to read files with DICOM format of femoral X-ray image,which was converted into files with bmp format.The image files with bmp format of the proximal femar X ray were introduced with Matlab software after regulation,and the two-dimensional contour data of femar were extracted.Prosthesis matched with the template was set in PhotoShop 7.0 software.The two-dimensional contour data of prosthetic femar were extracted in MATLAB software.The ANSYS software was used to establish the model of geometrical and two-dimensional nonlinearity finite element ncluding femur and femur-femoral stem.Stress distribution in the proximal femur was analyzed and compared by loading.MAIN OUTCOME MEASURES:Stress istribution of the proximal femur.RESULTS:Stress value and distribution of No.Ⅰ prosthesis and No.Ⅳ prosthesis in proximal femur were similar to the normal femar.Moreover,No.Ⅰ prosthesis was better than No.Ⅳ prosthesis.CONCLUSION:The biomechanics of femoral stem prostheses has been evaluated by analyzing and comparing the two-dimensional biomechanics of the femoral stem prostheses based on X-ray and template,which can offer support in optimal rosthesis selection.

Ionizing radiation can directly attack biological macromolecules including DNA, protein and lipids. Radiation can also damage cells indirectly by the formation of lots of free radicals through the radiolysis of surrounding water molecules. As the result, ion-izing radiation may make serious injury in human immune system, reproductive system and nervous system. Several synthetic radiopro-tectors have been used in clinic. However, most of them have some undesirable side effects. Hence, natural radioprotectors with high efficiency and low toxicity have been the focus of radioprotection field in recent years. In the paper, the recent research progress in the protection and repair effects of polysaccharides on radiation damage was reviewed.

Aiming at filling the vacancy in the study about mandibular movement, which mainly focuses on the field of biology at present, this study builds a mathematical model of 3-dimensional excursive movement of the mandible on Hanau articulator from the viewpoint of spatial mechanisms and analytical geometry. On the basis of the theory of spatial mechanisms, the freedom of motion of Hanau articulator is analyzed, and a hypothesis of constraints is presented, the objective of which is to restrict the mandibular movement. Based on the theory of analytical geometry, a series of mathematical expressions are derived to describe the 3-dimensional movement of the mandible mounted on the articulator. With the geometrical parameters of the articulator, these mathematical equations are solved by programming in Matlab 6.5 (a language for technical computing) and VC + +6.0. Therefore, the spatial path of the arbitrary point on the mandible can be precisely described when the upper body of Hanau articulator is guided along a specific direction. This study proves that the included angle between the plane of orientation and occlusal plane is positively related to the inclination of condylar guidance and incisal guidance, therefore, provides a theoretical foundation for Hanau's laws of articulation and the Hanau Quint. The future of dentistry is basically connected with the use of computer technology. This study will be useful for the further research of the dynamic occlusion to improve dental restorative procedures by realizing future replacement of the mechanical articulator with a virtual one.
Computer Simulation ; Dental Occlusion ; Humans ; Imaging, Three-Dimensional ; Mandible ; physiology ; Models, Theoretical ; Movement

Objective To determine the epidemiological and etiological characteristics of hand，foot，and mouth disease （HFMD） in Pujiang County from 2008 through 2020， so as to provide scientific evidence for prevention and control measures. Methods Descriptive epidemiological analysis was used to analyze HFMD cases retrieved in the Chinese Information System for Disease Control and Prevention in Pujiang County during 2008‒2020. Results From 2008 through 2020， a total of 9 393 cases were documented in Pujiang County， with an annual incidence of 182.3 per 100 000， showing a trend of alternating high-incidence and low-incidence years. The seasonal distribution was bimodal， and the incidence peaked in May-July and November-December. The incidence of HFMD in urban areas was significantly higher than that in rural areas， and the incidence was positively correlated with population density. Majority of cases （94.9%） were children under 5 years old， of which boys had higher incidence than girls. The number of documented cases was the highest among preschool children living in families and kindergartens， accounting for 97.3%. Totally， 558 cases were laboratory confirmed in Pujiang County in 2008-2020， of which severe cases were all caused by EV71 infection. Conclusion Enterovirus serotypes in HFMD have continually changed from 2008 through 2020 in Pujiang County. However， severe HFMD remains principally attributable to EV71 infection， suggesting that it is necessary to strengthen the surveillance on the etiology of HFMD. In addition， it warrants further promotion of EV71 vaccination.