Identification and characterization of a novel natural recombinant avian leucosis virus from Chinese indigenous chicken flock

Virus Genes - Avian leukosis virus (ALV) caused tremendous economic losses to poultry industry all over the world, especially in China. One natural recombinant ALV strain, designated as HB2015032,...     

Health effects of airborne particulate matter trace elements

The effects of airborne particulate matter （PM） trace elements on health are widely concerned nowadays. Many achievements have been made while many unknowns exist. This article reports the recent research progresses, describes the effects of exposure to PM trace elements on health epidemiological evidence, toxicology findings, and raises some questions for future studies.     

The roles of the N-terminal portions of various tachykinins in promoting salivation

OBJECTIVES: In order to determine the active sites for salivation of various tachykinins, the regulatory roles of the N-terminal portion of various newly-synthesized tachykinins were studied after i.p. injection of rats using the submandibular glands as model organs. METHODS: N-shortened oligopeptides from kassinin, eledoisin, neurokinins A (NKA) and NKB were synthesized by the multipin peptide synthesis method. Amino acids were eliminated one by one to form octa- to undeca-peptides adjoining the inactive or less active heptapeptides and various heptapeptides, in which an amino acid in position 8 (Xaa8), numbering as in an undecapeptide, was replaced with Tyr, Phe, Ile or Val. RESULTS: The N-terminal amino acids in positions 1 to 4 could be activators or inhibitors, depending on whether the C-terminal heptapeptide was inactive or less active. The Xaa8 residue, in combination with amino acids in positions 5 and 6, seemed to be very important in determining the sialogogic activity of a heptapeptide. The discrimination between NKA and NKB appeared due to the N-terminal amino acid sequence in positions I to 4 including Phe or Ser in position 6. CONCLUSIONS: It is concluded that the N-terminal amino acids in positions I to 4 serve as either activators or inhibitors depending upon the sialogogic activity of the C-terminal heptapeptide, in which particular amino acids in positions 5, 6 and 8 regulate its activity.     

三维放疗计划优化技术减少头颈部癌放射性口干症

目的：观察三维放疗计划优化技术减少头颈部癌放射性口干症的效果。方法：对三类头颈部癌（肿瘤位中线、偏一侧、近中线偏一侧）按常规放疗和优化技术分别作三维放疗计划。放疗优化技术包括放射进路优化、多野、适形放疗和加楔形板。对患者的肿瘤、腮腺和脊髓作三维剂量分布和剂量一容积DVH直方图分析。20例头颈部癌放疗患者分成常规放疗组和新技术（优化）组行放射治疗，记录放疗前、放疗中、放疗后及随访期患者的口干症评分和全唾液量。结果：肿瘤位一侧及近中线偏一侧时，常规和新技术放疗时健侧腮腺放射剂量分别为51.8-64.3Gy和0.4-1.4Gy；肿瘤位中线时常规和新技术放疗腮腺放射剂量分别为51.8Gy和24.7Gy；放疗结束时，新技术组口干症发生率1/12（8.3％）。随访4-6月后降为0，放疗结束时常规放疗组口干症发生率7/8（87.5％），随访4-6月后为4/8（50％）。结论：三维放疗计划优化技术可以明显减少头颈部癌患者放疗后口干症的发生。     

Electrochemical aspects of the formation of Bi2Te3 thin film via the route of ECALE

A Bi₂Te₃ VA–VIA group compound thin film was prepared via the route of electrochemical atomic layer epitaxy in this paper. The dependence of thin film formation on the electrochemical conditions (such as deposition potential control, supporting electrolyte and substrate) was studied, and the formation process of Bi₂Te₃ film was determined. The results show that Bi upd on Pt occurs at more negative potential in a HNO₃ supporting electrolyte than in a HClO₄ supporting electrolyte, and the Te upd peak moves to a more negative potential in HClO₄ supporting electrolyte solution than that in HNO₃ solution; Both Te and Bi upd on an Ag substrate occur at more negative potentials than that on a Pt substrate. In order to reach steady state deposition, a potential adjustment is necessary for the first 30 or more cycles of each component. After deposition of this initial ‘buffer layer’, the potentials can be kept constant for the remaining cycles. The effect of the slope of the shift of potential used to deposit the first 30 atomic layers of Bi and Te on the deposit has also been investigated. The deposit exhibits a two phase mixture of excess elemental Bi and Bi₂Te₃ compound when the slope is larger than ?4 mV/p (p indicates per cycle); a single-phase Bi₂Te₃ compound was obtained at a slope of ?6 mV/p, and Bi₄Te₃ compound also appears in the deposit along with Bi₂Te₃ when the slope is decreased to a more negative value of ?10 mV/p.     

微型种植钉的长度直径对生物力学的影响

目的对比评价临床常用的3种类型(不同长度、直径)微型种植钉的生物力学特点。方法应用种植钉48枚,新西兰大白兔8只。采用拉出试验,扭转强度试验,在即刻与愈合4周后进行生物力学测量。结果长度为6mm,直径为1.9mm的种植钉相对于同等长度,直径为1.5mm的种植钉在“种植后即刻”与“愈合4周”时,最大剪切力均表现出显著性优势。愈合4周后,直径为1.9mm的种植体在最大扭转强度上表现出显著性的优势。结论在骨质量较差的部位选择较大直径的种植体有利于种植体的稳定。     

上颌半口义齿金属基托的计算机辅助设计

目的 :在自行重建无牙颌三维数据模型的基础上设计上颌半口义齿金属基托数字模型。方法 :采用数控铣床及新型层析数据采集系统 ,通过对标准无牙颌模型的层切 ,二维轮廓数据获取及计算 ,重建无牙颌模型 ,在此数据基础上 ,通过SURFACER软件 ,设计上颌半口义齿金属基托。结果 :获得无牙颌三维数据及上颌金属基托的数据文件。结论 :通过新型层析系统可以实现对无牙颌三维建模 ;在此基础上设计的三维数字基托可为进一步激光立体成形制作奠定基础。     

Immunocytochemical examination of immune cells in periapical granulomata and odontogenic cysts

Monoclonal antibodies (mAbs) were used to determine the presence and distribution of immune cells including lymphocytes, macrophages and Langerhans cells, in normal periodontal ligament, periapical granulomata, periapical cysts and dental developmental cysts. Isolated T-lymphocytes, but not B-lymphocytes, were detected in specimens of non-inflamed periodontal ligament. Increased numbers of T and B lymphocytes were found in all of the lesions examined. Monocytes/macrophages were associated with most periapical granulomata, dental developmental cysts and all periapical cysts. Langerhans cells, intraepithelial lymphocytes, and monocytes/macrophages were not detected in the rests of Malassez but were found in some epithelia within periapical granulomata and in most epithelial linings of odontogenic cysts. Increased numbers of immune cells were seen around proliferative epithelia and adjacent to the epithelial linings of cysts. Epithelium, particularly that of odontogenic cysts, showed positive reactions for HLA-Dr, lysozyme and for α-1 antitrypsin. The presence of immune cells in periapical granulomata and odontogenic cysts, suggests that cell-mediated and humoral immunoreactions occur in these lesions and may be associated with the epithelial proliferation within the periapical lesions.     

铸造义齿中网状支架的设计

铸造义齿中网状支架的设计李景辉，宋培智，陈官辉，季秋杰，卢玉春，高银凤在可摘局部义齿修复中，网状支架的合理设计既增加了义齿的强度，又具有传递咬力、分散力、保护口腔内软硬组织的功能［１］。常用形态为园孔形、方格形、楼梯的，网状形、三角形、倒锥形、栅栏形...     

网络在牙体牙髓疾病诊治中的应用

计算机网络（computer network）作为计算机技术和通信技术相结合的产物，它通过通信设备和线路将不同地理位置上的具有独立功能的计算机互连起来，在功能完备的网络软件支持下，实现资源共享和信息交换。1972年以太网的开发实现了真正意义上的计算机网络，从此各种局域网、广域网相继出现，迅速发展。