Objective To develop a DNA microarray for HLA-DR1,DR51 group genotyping. Methods According to the specific allelic sequences coding HLA-DR1,DR51 loci,HLA- DR1,DR51 group typing probes which were immobilized on a glass support were synthesized.A pair of group-specific primers labeled by the Cy5-dCTP were designed,then the primers were used in the PCR,thus the PCR products were labeled with Cy5.The labeled PCR products were hybridized with array.The signals were scanned by scanner and analyzed by image software.The typing results were confirmed by standard DNA and PCR-SSO. Results A total of 130 samples were typed by this DNA array.There were 34 HLA-DR1,DR51 group loci typed by DNA array.Among them,18 loci were DR15,8 were DR16,6 were DR10 and 2 were DR1.No false positive or false negative typing results occurred.The accuracy and reproducibility were 100% and the overall time of genotyping was about 3.5 hours. Conclusions DNA array technique is a precise,rapid molecular method of high resolution power and high specificity for HLA-DR1,DR51 genotyping,which is applicable to clinical transplant practice.

Objective To develop an oligoneucleotide array for HLA-DR52 group rapid genotyping.Methods According to the special allele sequences of HLA-DRB loci in Chinese Han's population, HLA-DR52 group typing probes which were immobilized on a glass supports were synthesized. A pair of group-special primers labeled by the Cy5-dCTP were designed and were used in the PCR. The labeled PCR products with Cy5 were hybridized with array. The signals were scanned by a scanner and analyzed by Image software. 83 samples were typed by this array and the results were compared with PCR-SSP typing.Results Among 57 HLA-DR52 group loci typed by PCR-SSP,2 samples had no HLA-DR52 loci typed by array,3 DR52 group homozygotes typed by PCR-SSP were actually heterozygotes by array. The other 1 non-DR52 group homozygote identified by PCR-SSP was a heterozygote with one DR52 group locus. Conclusion The oligoneucleotide array technique is a precise, rapid molecular method for HLA-DR52 genotyping. Compared with PCR-SSP method, the genotyping chip is more sensitive and intuitionistic and suitable for clinic practice.

Objective:To establish a new method performed on an DNA chip for genotyping HLA DR and supply a new view.Methods:According to the particular sequence of HLA DR exon2,HLA DR genotyping Chip was made,then the labeled PCR products hybridized with them,the signals were sanned by sanner and analyzed by Imagene software.70 standard DNA and 200 donor recipients have been genotyped and some of samples have been sequenced.Results:The experimental results showed that the HLA DR genotyping chip made are accurate and sensitive.Thirty alleles of HLA DR were accurately distinguished and its overall time of DNA typing was 3 hours.Conclusion:This proved that the DNA Microarray technique is good for DR genotyping and high resolution,high specificity,well reproducibility.Compared with PCR SSP and PCR SSO methods,the genotyping chip method is more intuitionistic and has the advantage of integration.It can also genotype HLA A,B alleles and many persons in a chip at the same time.It is more suitable for clinical application and establishment of marrow bank and umbilical cord bank.

RNA has received m ore attention in the field of forensic m edicine and the developm ent of the new biological m arkers based on RNA show s great significance in the analysis of com plex cases. circular RNA (circRNA ) is a kind of non-coding RNA w hich is w idely reported recently. A lthough the regulatory m echanism s of generation and expression are not fully clear, the existing research indicates that circRNA has im portant biological functions. C ircRNA has a cell-type-specific expression w ith great stability and a high expression level, w hich m akes it m eaningful in forensic applications potentially. In this paper, the research progress, the generation and regulation of circRNA as w ell as its biological characteristics and functions are sum m arized, w hich w ill provide references for related studies and foren-sic applications.

Identifying the origin of body fluids left at a crime scene can give a significant insight into crime scene reconstruction by supporting a link betw een sample donors and actual criminal acts. How ev-er, the conventional body fluid identification methods are prone to various limitations, such as time con-sumption, intensive labor, nonparallel manner, varying degrees of sensitivity and limited specificity. Re-cently, the analysis of cell-specific messenger RNA expression (mRNA profiling) has been proposed to supplant conventional methods for body fluid identification. Since 2011, the collaborative exercises have been organized by the European DNA Profiling Group (EDNAP ) in order to evaluate the robustness and reproducibility of mRNA profiling for body fluid identification. The major advantages of mRNA profil-ing, compared to the conventional methods, include higher sensitivity, greater specificity, the ability of detecting several body fluids in one multiplex reaction, and compatibilitywith current DNA extraction and analysis procedure. In the current review ,we provided an overview of the present know ledge and detection methodologies of mRNA profiling for forensic body fluid identification and discussed its possi-ble practical application to forensic casew ork.

Objective To investigate Insertion/Deletion (InDel) polymorphism on the X chromosome and to screen 18 InDel loci for the Chinese Han population as a forensic DNA typing system auxiliary. Meth-ods Eighteen X-InDel markers were selected using the Human Genome Browser and dbSNP database. Multiplex PCR primer pairs of selected X-InDel markers were designed using Primer 3 software and di-vided into 3 groups according to the amplified fragment length, labeled by FAM, HEX and TAMRA fluorescence dye, respectively. The population genetics research and comparative analysis of Chinese Han nationality and 4 main minorities, the Hui, Wei, Mongol, and Tibetan nationalities, were investigated with the system. Results A new multiplex genotyping system, named InDel X-18PLEX, was successfully developed and validated, consisted of 18 X-InDel markers on the X chromosome and 1 Amelogenin gen-der marker. No deviation from Hardy-Weinberg equilibrium expectations was detected in the distribution of genotypes in the 5 investigated ethnic groups. However, there was significant difference between their distributions. From the investigation of Han nationality, high female (0.999 999 4) and male (0.999 88) overall discrimination power values were obtained, as well as high overall mean exclusion chance values in trios (0.999 992) and in duos (0.99). Conclusion InDel X-18PLEX meets the requirements as a forensic DNA complementary kit, providing effective supplementary analytical tools for difficult cases.

Species identification of biological samples is widely used in such fields as forensic science and food industry. A variety of accurate and reliable methods have been developed in recent years. The cur-rent reviewshows common target genes and screening criteria suitable for species identification, and de-scribed various DNA-based molecular biology methods about species identification. Additionally, it dis-cusses the future development of species identification combined with real-time PCR and sequencing technologies.

Objective To evaluate the feasibility of the porous titanium/chitosan/hydroxyapatite (Ti/Ch/HA) composite scaffold as a bone repair substitute.Methods Additive manufacturing (3D printing) technology was used to fabricate porous Ti scaffolds as supporting structures.Chitosan/hydroxyapatite (Ch/HA) sponge was prepared within the macro-pores of Ti scaffolds using freeze drying technology.Thus,a kind of composite porous Ti/Ch/HA scaffold with good cell affinity was obtained.Osteoblastic cells were seeded and cultured in pure porous Ti scaffolds and composite Ti/Ch/HA scaffolds for 7 days.The cellular morphology,seeding efficiency and proliferation were examined and compared between the 2 kinds of scaffolds using scanning electron microscopy (SEM) and MTT assay.Results The SEM examination showed that the macro-pores of Ti/Ch/HA scaffolds were full of the composite sponge structure of Ch/HA,with a micropore size of 50 to 200 μm.Like the pure porous Ti scaffolds,composite Ti/Ch/HA ones have a compressive strength of 168.2 to 192.6 MPa,a yielding strength of 137.1 to 154.1 MPa,and a Young's modulus of 3.21 to 4.51 GPa.After culture for 7 days,a large number of flat cells adhered onto the surface of Ti scaffolds while the cells adhering onto the Ti/Ch/HA composite scaffolds were fusiform.The seeding efficiency of osteoblastic cells in the composite Ti/Ch/HA scaffolds (73.218％ ± 3.748％) was significantly higher than that in the pure porous Ti scaffolds (21.352％ ±4.365％) (P ＜0.05);the OD value of the composite Ti/Ch/HA scaffolds (0.783 ±0.043) was significantly higher than that of the pure porous Ti scaffolds (0.382 ± 0.036) (P ＜ 0.05).Conclusions Ti/Ch/HA composite scaffolds can match human bone in mechanical properties.Compared with pure porous Ti scaffolds,the Ti/Ch/HA composite ones are more suitable for adhesion and proliferation of osteoblasts,making them an ideal kind of bone repair substitute.

Objective In order to avoid potential injuries imposed to human body,it could be feasible to use the musculoskeletal models which can be reconstructed from the cadaver color cryosection(CCC)images,computerized tomography(CT)images,magnetic resonance(MR)images or other images to analyze the dynamic properties of muscles in vivo during human movement.Mothod We reconstruct the lower limb musculoskeletal model and define the uniform ioint coordinate system(JCS)on the model and the subject.The coordinate transformation of the muscle attachment points both on the model and the subject is described in detail.Results The length and the moment arm of the biceps femoris(short head)during knee flexion are calculated and analyzed.Conclusion This method plays an important role in improving the kinematics and dynamic simulation and the muscle force estimation.

Objective To compare the compression properties of articular cartilage and polyinyl alcohol hydro-gel(PVA-H)as artificial carlage.Method Unconfined compression tests were conducted on articular card-lage and PVA-H,including stress-strain tests,creep tests and stress relaxation tests.The stress-strain rela-tionship of articular cartilage and PVA-H were measured.Result The compression modulus of articular card-lage was higher than that of PVA hydrogel.The average compression modulus of articular cartilage and PVA hydrogel was(3.6492±0.6199)Mpa and(1.5951±0.1469)Mpa,respectively.Condusions The experimental results revealed the differences existed between articular cartilage and PVA-H and this would be useful to fur-ther improve the mechanical properties of artificial cartilage.