“学生腔”杂谈

很多学生在写作中经常犯一个错误，那就是对于不同身份、不同文化层次的人物写作套路几乎相同，这就是“学生腔”。“学生腔”严重影响了学生作文的质量。所以，学生要想走出这个困境，就必须弄清楚写作对象的特点；深入生活，学习群众语言，不能闭门造车；注意不同文体的用语习惯和特点，根据文体来选择合适的语言。

Prospect of Functional Salivary Gland Enhancement with Biomedical Strategies for Head and Neck Cancers

Xerostomia is the main complication inflicting head and neck cancer patients treated with radiotherapy.Conventional treatment is not very effective in alleviating this morbidity.Biomedical strategies such as gene transfer and tissue engineering have made substantial progress that will potentially lead to successful new treatment options for this condition.This report reviews the process of radiation damage to the salivary glands and the advances in functional salivary gland enhancement with these two brand-new technologies.

Determination of Fungal Colonization in the Oral Cavity of College Students

In recent years, an increase in opportunistic fungal colonization in the oral cavity in immunocompetent patients （IC） has been observed. In the bibliography, the most observable genre is Candida and less frequently found are other opportunistic such as Aspergillus, Rhizopus, Cryptococcus, and others. The authors determined the presence of fungi in the oral cavity of IC students, and their relationship with the concentration of secretory IgA in saliva. To this end, we collected 50 samples of oral cavity swabs, which underwent direct examination and culture in Sabouraud dextrose agar with chloramphenicol. For its identification, CHROMagar Candida and API Candida （BioMerieux） were used. We obtained nine positive cultures （7 Candida albicans and 2 Saccharomyses cerevisiae）, which represented 18% of the studied population. Throughout radial immunodiffusion （RID plates-PLATE）, we determined the concentration of secretory IgA. No relationship was observed between the colonized group and group that was not colinized. The colonization rate found is below the one described in the bibliography （30% to 50%）. However, these opportunistic fungi cause transitory colonization with no clinical relevance in IC patients and, its percentage can vary according to the studied population.

Studies on Biological Characteristics of Rabbit Oral Mucosal Epithelial Cells

Objective:The biological characteristics of rabbit oral mucosal epithelial cells(OMECs) were studied and the suitable procedure for the culture of OMECs was explored.Methods:Cultured OMECs by different surface disinfection,by different Dispase Ⅱ preparation,in different medium,in different calciumion concentration of K-SFM medium.Results:Microbial contamination of cell culture could significantly reduce with 2% iodine solution used for sterilization of oral cavity before cell culture.The OMECs digested with Dispase Ⅱin K-SFM could attach to the culture flask quickly,the OMECs digested with Dispase Ⅱ in PBS rare attached to the culture flask.The proliferations of OMECs cultured in 0 or 0.09 mmol/L calcium concentrations of K-SFM medium showed not statistically significant.the OMECs grew fast with serum,but it was easy to differentiate into fibroblast-like cells.Conclusion:OMECs could grow well and had the typical oral mucosal epithelial cell morphology by the procedure that described in this experiments.

Bose-Einstein Condensation of Photons and Photon Pairs

We investigate the Bose-Einstein condensation of photons and photon pairs in a two-dimension optical microcavity. We find that in the paraxial approximation, the mixed gas of photons and photon pairs is formally equivalent to a two dimension system of massive bosons with non-vanishing chemical potential, which implies the existence of two possible condensate phase. We also discuss the quantum phase transition of the system and obtain the critical point analytically. Moreover, we find that the quantum phase transition of the system can be interpreted as second harmonic generation.

A rabbit model of graded primary mechanical injury to brainstem

Objective： To introduce a new animal model of graded mechanical primary brainstem injury （BSI）. Methods： Altogether 45 rabbits were subjected to BSI by type II biological impact machine designed by the Third Military Medical University. The animals were divided into 4 experimental groups （n=10） and 1 control group （n=5） ac- cording to different magnitudes of impact pressure imposed on the occipital nodule： Group 1,500-520 kPa; Group 2, 520- 540 kPa; Group 3,540-560 kPa; Group 4, 560-580 kPa and Group 5, 0 kPa with 20 kPa increase in each grade. The im- pact depth was a constant 0.5 cm. After injury, the clinical symptoms and signs as well as pathological changes were observed. Results： Rabbits in Group 1 revealed mild physiologi- cal reaction of BSI. They had localized cerebral contusion with punctate hemorrhage and subarachnoid hemorrhage （SAH） was limited to the peripheral tissues at the impact area. In Group 2, obvious physiological reaction was observed. Local pathological lesions reached the superfi- cial layer of brainstem tissues; focal hemorrhage and girdle- shaped SAH in basilar pon were observed under microscope. In Group 3, BSI was more severe with a long respiratory depression. Pathological lesions reached the inner portionof brainstem with massive hemorrhage and the whole brainstem was wrapped by subarachnoid hematoma. In Group 4, most rabbits died due to severe BSI. Pathological lesions deepened to the central brainstem with wide patho- logical change, rapture of the medulla oblongata central canal. Group 5 was the control group, with normal brainstem structure and no lesion observed. Conclusion： This model successfully simulates differ- ent levels ofbrainstem mechanical injury and clearly shows the subsequent pathological changes following injury. It takes two external parameters （impact pressure and depth） and has a similar injury mechanism to clinical accelerating BSI. Moreover it is reproducible and stable, thus being be- neficial for exploring pathophysiological mechanism, diag- nosis and forensic identification of various degrees of BSI.

Fast Generation of Einstein–Podolsky–Rosen States for Two Cavity Modes with a Collection of Driven Atoms

We propose an efficient scheme for realizing two-mode squeezing for two cavity modes with an atomic ensemble trapped in the cavity and driven by two classical fields. Through a suitable choice of the driving classical fields, the evolution dynamics of the two cavity modes is decoupled with the atomic system and described by a two-mode squeezing operator. We show that a highly squeezed state can be obtained at the output even with a bad cavity. The required experimental techniques are within the scope of what can be obtained in the BEG-cavity setup.