Objective To apply the three-dimensional pre-operative simulation and intra-operative real-time navigation in the reconstruction of old maxillofacial fractures so as to increase the surgical precision. Methods Six patients with old maxillofacial fractures were enrolled, and the diagnosis of unilateral old maxillofacial fractures was confirmed by clinical and imaging examinations. Virtual three-dimensional skull models were reconstructed from pre-operative CT images. The fractured bone was moved or rotated, and was reposed in a desired site according to the mirrored part from the healthy side. After patient-to-image registration, the surgical instruments and patients were tracked in real-time by optical tracking system during operation, and in this way the maxillofacial fractures were reposed satisfactorily guided by the virtual image. Results Three-dimensional simulation before operation and real-time navigation of patients and instruments during operation were realized. The error of registration was less than 1 mm. The post-operative CT examinations of these six patients revealed that the fracture reposition was same to the pre-operative planning, and the difference between them was less than 1.5 mm. The operations were minimally-invasive, with no complications. Conclusion Computer-aided surgical simulation and navigation system can effectively increase the surgical precision of reconstruction of old maxillofacial fractures.

Objective To analyze the imaging features and its value in diagnosing primary malignant fibrous histiocytoma(MFH) of bone.Methods Imaging features(X-ray,CT,MRI) in 8 cases of MFH confirmed pathologically,and were retrospectively reviewed.Results The location of lesions in 6 cases was in upper femur,2 cases was in upper tibilar.Worm-eaten-like bone destruction withindistinct margin was presented on X-ray film,some lesions showed slightly marginal sclerosis.Tumors were soft tissue density on CT(CT value was 34~35 HU).The masses of soft tissue were showed much distinct.Conclusion The primary MFH of bone is not of characteristic imaging findings.It can improve obviously the diagnosis of the disease by the comprehensive analysis of the imaging data.

Objective To explore the MR imaging of reverse and separation of meniscal articular capsule.Methods MR imaging of reverse and separation of meniscus articular capsule confirmed by surgery and arthroscope were analyzed retrospectively in 8 cases.Results The “Butterfly knot sign” disappeared and was replaced with fluid signal on the sagittal slice of meniscal body in 8 cases. Part of back angle remained in 3 cases. “Double anterior cruciate ligament sign” was showed on one side of middle sagittal slice in 7 cases. “Reverse meniscus sign” was revealed in intercondylar fossa on the coronary view in ~8 cases. Abnormal high signal was showed in the injured meniscus in 6 cases. Abnormal high signal was detected in the opposite meniscus in 5 cases.Conclusion The MR findings of reverse and separation of meniscus articular capsule include disappearance of “butterfly knot sign”, appearance of “reverse meniscus sign” and “double anterior cruciate ligament sign”. The diagnosis would be established if the former 2 signs were present or all the 3 signs were present simultaneously.

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.

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.

Objective To investigate the stress distribution in the abutment and supporting tissues of distal-extension removable partial dentures with mesial and distal occlusal rest under loading. Methods A modular denture model was used to build a model of mandibular dentition defect ( 765┬567 loss) with HyperMesh 7.0 software. Prosthetics with mesial (M model) and distal occlusal rest (D model) were designed with UG 5.0 software, and the finite element models were completed with HyperMesh 7.0 software. The stress distribution was analyzed in the abutment and supporting tissues of distal-extension removable partial dentures with mesial and distal occlusal rest when bilateral vertical forces were applied. Results Compared with M model, D model provided much larger maximum stress in abutments and periodontal membrane. Stress of D model mainly concentrated on roots of 4┬4 , while that of M model uniformly distributed on roots of 43┬34 . The maximum stress of M model was significantly larger than that of D model on the mucosa of edentulous region. The maximum stress on alveolar bone of two models' edentulous region was equal, while the stress of M model distributed more widely. Conclusion It is prior to select mesial occlusal rest in distal-extension removable partial dentures.

In order to find the most suitable algorithm of T-wave end point detection for clinical detection, we tested three methods, which are not just dependent on the threshold value of T-wave end point detection, i. e. wavelet method, cumulative point area method and trapezium area method, in PhysioNet QT database (20 records with 3 569 beats each). We analyzed and compared their detection performance. First, we used the wavelet method to locate the QRS complex and T-wave. Then we divided the T-wave into four morphologies, and we used the three algorithms mentioned above to detect T-wave end point. Finally, we proposed an adaptive selection T-wave end point detection algorithm based on T-wave morphology and tested it with experiments. The results showed that this adaptive selection method had better detection performance than that of the single T-wave end point detection algorithm. The sensitivity, positive predictive value and the average time errors were 98.93%, 99.11% and (--2.33 ± 19.70) ms, respectively. Consequently, it can be concluded that the adaptive selection algorithm based on T-wave morphology improves the efficiency of T-wave end point detection.
Algorithms ; Electrocardiography ; Humans ; Wavelet Analysis