Quantum dots( QDs) as a new type of nanostructured luminescent materials have been widely used in biology, materials science, and physical optics. QD-based biosensors can rapidly and accurately detect biological macromolecules or inorganic molecules both in vivo and in vitro. The surface of QDs, prior to their biological detection applications, needed to be modified to enhance their fluorescence properties and lower their biological toxicity. Currently, the surface modification technologies mainly include polymer modification, thiol compounds modification, mercapto propionic acid compounds modification and organic groups modification. Various biosensors can be developed by adopting different modification techniques, which have been adopted to locate and track a variety of biological molecules in vivo. Although a large number of literatures have reported the biological applications of QD-based biosensors, rare systematic reviews of surface modification technologies on QDs have been witnessed. In this paper, we reviewed the surface modification technologies of QDs in biosensors and their medical applications.

The educational equity includes the educational rights equity and opportunity equality. Nowadays, real non-equality phenomena exist in our country including in the field of higher education because of many influential factors that affect the educational equity. In the article the author makes the philosophical thinking about the equity and efficiency in higher education through the analysis of these non-equality phenomena, and puts forward that we must hold the principle that efficiency is first, and equity should be stressed at the same time under the condition of insufficient education resource. Meanwhile the educational equity should be enhanced according to the system arrangement and policy adjustment.

BACKGROUND:The lumbar interspinous device, as a kind of non-fusion technology has been extensively applied in the clinic and exerts superiority in biomechanics compared with the traditional fusion technology. With the development of prosthesis design and impanation technology, it reveals a better application prospect. OBJECTIVE:To review the biomechanics and finite element analysis of lumbar interspinous devices. METHODS:The first author retrieved the databases of CNKI, WanFang, PubMed and SpringerLink using the keywords of“lumbar spine, interspinous devices, biomechanics, finite element analysis”in Chinese and English, respectively. Researches related to the biomechanics and finite element analysis of lumbar interspinous devices were included and repeated researches were excluded. A total of 44 literatures were enrol ed for review, including 8 Chinese and 36 English literatures. RESULTS AND CONCLUSION:(1) Biomechanical y, several interpinous devices, which are commonly used in the clinic, can increase the stability of the implanted segment in sagittal alignment by limiting the range of flexion-extension, with no significant change in lateral bending and axial rotation. (2) Few studies analyze the influence of the implant size and placement on the implanted segment and on the adjacent segments. (3) Through the stress nephogram, three-dimension finite element analysis can intuitively analyze the changes of the stress distribution in the intervertebral disc, isthmus and facet joints before and after implantation. Both biomechanical studies and finite element analysis indicate that interspinous devices can share the load of the disc and facet joints, and at the same time, make no effect on the range of motion and stress of the adjacent segment. (4) In conclusion, the short-term biomechanical advantage of the interspinous devices is obvious, but further studies are needed. The finite element analysis can simulate different body physical environment, and can analyze mechanical distribution changes after implantation, which is an effective way to evaluate the mechanical mechanism of the interspinous devices.

Human immunodeficiency virus ( HIV) is commonly transmitted through blood transfu-sion, sexual contact and mother-to-child transmission. The number of patients with HIV infection has kept growing in the last three decades. Although the wide application of antiretroviral therapy ( ART) has effec-tively suppressed the replication of HIV, the emergence of drug resistant mutants compromises the efficacy of ART. What is worse is that there has been transmission of drug resistance strains in ART-na?ve HIV-infected individuals. This review describes the distribution of transmitted drug resistance strains in different regions and high risk population as well as the factors associated with the transmission in recent years.

OBJECTIVE To explore the predisposing factors of pharyngo-cutaneous fistulas after surgical treatment of laryngeal cancer. METHODS A retrospective study of 757 patients who underwent laryngectomy during a 10-year period was carried out. RESULTS The occurrence rate of post-laryngectomy pharyngo-cutaneous fistula was 4.2 %. Single-factor analysis showed that parameters related to the occurrence rate of post-laryngectomy pharyngo-cutaneous fistula included clinical stage of tumor, appearance of post-operative infection, undergoing of pre-operative radiotherapy, and pre-operative nutrition states. CONCLUSION Pharyngo-cutaneous fistulas appears more frequently in patients with T3 and T4 tumor and who underwent pre-operative radiotherapy. Skillful operative technique and effective prevention of post-operative infection may contribute toward reducing the incidence of pharyngo-cutaneous fistulas after surgical treatment of laryngeal cancer.

Objective: To develop a PCR method for detecting S treptococcus sobrinus (S.s) in conventional culture. Method: A pair of specific primers were designed from the dexA gene of S.s , the genome DNA of 12 strains of Mutans Streptococci (8 serotypes from a ～h) and 23 species of the bacteria which were commonly found in oral cavity wer e tested by PCR amplification, the PCR products were identified by electrophore sis. Result: Only S.s of serotype d and g could produ ce 277 bp DNA fragments, and the PCR method could detect less than 1 000 copies of S.s. Conclusion: PCR method is specific and sen sitive in the detection of S.s.

Object To study the apoptosis induced by sodium artesunate (SA) in human liver cancer cells and its molecular mechanism. Methods Induction of the apoptosis was analyzed by fluorescent microscope, transmission electron micrograph and flow lytometry based on drug treated BEL-7402. Expressions of p53, p21 and bc1-2 were determined by Western blot. Results The expression level of p53 and p21 had no change remarkbly, but the expression level of bc1-2 was reduced compared to that of the control group after the human liver cancer cells were treated by SA. Conclusion The apoptosis in human liver cancer cells (BEL-7402) may be induced by SA, the molecular mechanism of apoptosis may be p53-independent, that is no relative to p53 and p21. Otherwise, it is relative to bc1-2 down-regulation.

Objective To observe the effect of conductive education(CE) combined rehabilitation therapy on stroke patients.Methods 57 stroke patients were assigned to experiment group (25 cases) and control group (32 cases). Both groups received rehabilitation therapy, meanwhile，experiment group received CE. Main outcome measure：①FMA; ②Barthel Index(BI); ③Social function action questionnaire(SFA).Results FMA, BI and SFA increased significantly(P＜0.05)in both groups after treatment. BI and SFA improved more in experiment group than those of control group between group comparisons(P＜0.05).Conclusion Conductive education combined rehabilitation therapy could improve the motor function, ability of daily living and social function action on stroke patients.

Objective To investigate the imaging findings of primary bone malignant fibrous histiocytoma (PBMFH) in long bone. Methods MRI and XV ray examinations were performed in 10 patients with PBMFH in long bone confirmed by histology. CT scans were performed in 6 cases. Results Nine cases had single and 1 case had multiple lesions of single bone. Seven cases showed osteolytic bone destruction, and 3 cases showed mixed bone destruction. Only 1 case showed periosteal reaction. Gross bony ridge was seen in 3 cases on CT scan. All the patients demonstrated isointensity or hypointensity on T1WI, and slight hyperintensity signal on T2WI. Necrosis was seen in the lesion of 10 cases. Four cases showed obvious but heterogeneous enhancement after contrast medium injection. Eight cases had soft tissue mass beyond the scope of bone destruction. Conclusions Some imaging features may suggest the diagnosis of PBMFH in long bone.

AIM: To investigate the changes of plasma glutathione peroxidase (GSH-PX) and catalase (CAT) activities in nude mice (NM) bearing human nasopharyngeal carcinoma (NPC) and observe the effect of naja naja atra venom (NNAV) on them. METHODS: Plasma GSH-PX and CAT activities in human NPC bearing NM treated ( i.p. ) by low, middle or high concentration NNAV solution (1 mg/L, 5 mg/L, 10 mg/L) were determined by colorimetry. RESULTS: Plasma CAT activity (16 450 U/L) in NM bearing tumor group decreased significantly in comparison with the control group (20 680 U/L)(P0.05). Treated by low, middle or high concentration NNAV solution, CAT activities of three NM bearing tumor groups (20 570 U/L, 23 090 U/L, 21 280 U/L ) were higher than that of the NM bearing tumor group without NNAV treatment (16 450 U/L) (P0.05). GSH-PX activities of the three groups (especially high concentration group) were higher than that of the group without NNAV treatment (P