Optimal vaccine stockpile design for an eradicated disease: Application to polio

Eradication of a disease promises significant health and financial benefits. Preserving those benefits, hopefully in perpetuity, requires preparing for the possibility that the causal agent could re-emerge (unintentionally or intentionally). In the case of a vaccine-preventable disease, creation and planning for the use of a vaccine stockpile becomes a primary concern. Doing so requires consideration of the dynamics at different levels, including the stockpile supply chain and transmission of the causal agent. This paper develops a mathematical framework for determining the optimal management of a vaccine stockpile over time. We apply the framework to the polio vaccine stockpile for the post-eradication era and present examples of solutions to one possible framing of the optimization problem. We use the framework to discuss issues relevant to the development and use of the polio vaccine stockpile, including capacity constraints, production and filling delays, risks associated with the stockpile, dynamics and uncertainty of vaccine needs, issues of funding, location, and serotype dependent behavior, and the implications of likely changes over time that might occur. This framework serves as a helpful context for discussions and analyses related to the process of designing and maintaining a stockpile for an eradicated disease.     

摆动从动杆盘状凸轮机构的运动设计——同时考虑压力角和最小曲率半径的优化设计

本文对摆动从动杆盘状凸轮机构的最大压力角和最小曲率半径问题进行了详细的讨论。根据优化原理,同时考虑许用压力角和最小曲率半径,对摆动从动杆盘状凸轮机构进行了最优化设计。在仅给出摆杆运动规律、摆杆最大摆角和相应凸轮转角的情况下,直接确定凸轮的最小基圆半径、摆杆长度和摆杆初始位置角。     

Comparison of the biomechanical 3D efficiency of different brace designs for the treatment of scoliosis using a finite element model

The biomechanical influence of thoraco-lumbo-sacral bracing, a commonly employed treatment in scoliosis, is still not fully understood. The aim of this study was to compare the immediate corrections generated by different virtual braces using a patient-specific finite element model (FEM) and to analyze the most influential design factors. The 3D geometry of three patients presenting different types of curves was acquired with a multi-view X-ray technique and surface topography. A personalized FEM of the patients’ trunk and a parametric model of a virtual custom-fit brace were then created. The installation of the braces on the patients was simulated. The influence of 15 design factors on the 3D correction generated by the brace was evaluated following a design of experiments simulation protocol allowing computing the main and two-way interaction effects of the design factors. A total of 12,288 different braces were tested. Results showed a great variability of the braces effectiveness. Of the 15 design factors investigated, according to the 2 modalities chosen for each one, the 5 most influential design factors were the position of the brace opening (posterior vs. anterior), the strap tension, the trochanter extension side, the lordosis design and the rigid shell shape. The position of the brace opening modified the correction mechanism. The trochanter extension position influenced the efficiency of the thoracic and lumbar pads by modifying their lever arm. Increasing the strap tension improved corrections of coronal curves. The lordosis design had an influence in the sagittal plane but not in the coronal plane. This study could help to better understand the brace biomechanics and to rationalize and optimize their design.     

全胸腔镜肺叶切除手术操作流程及技巧的优化:北京大学人民医院经验

目的 总结北京大学人民医院全胸腔镜肺叶切除手术的操作流程和技巧的优化改进经验.方法 2006年9月至2010年8月连续开展全胸腔镜肺叶切除手术408例,男214例,女194例,平均年龄58.6岁.实体肿瘤平均最大径30.1 mm.手术采用双腔气管插管全身麻醉,健侧单肺通气.胸腔镜观察口选择第7或8肋间腋后线,长1.5 cm;辅助操作切口选择在肩胛下角线第7或8肋间,长1.5 cm;主操作口选择在第4或第5肋间腋前线,长约4 cm,无需放置开胸器,不牵开肋骨.全部操作过程完全在胸腔镜下完成.术者位于病人前侧,双手分别握持吸引器和电凝钩,在主操作口内进行操作;助手位于病人背侧,使用卵圆钳经辅助操作口帮助牵拉显露.基本操作顺序与传统开胸肺叶切除相同.肺癌病人均清扫纵隔淋巴结:肿瘤位于右侧,清扫2、4、3A、3P、7、8、9、10组淋巴结;左侧清扫3、5、6、7、8、9、10组淋巴结,必要时清扫第4组淋巴结.结果 全组手术顺利,围手术期死亡1例,无严重并发症发生.平均手术时间195 min,平均术中出血249 ml.术后病理良性疾病86例,恶性疾病322例.全组中转开胸35例,中转开胸率8.6%.术后轻微并发症48例,并发症发生率11.8%.术后平均带胸管时间7.9天,术后平均住院天数10.9天.结论 全胸腔镜肺叶切除手术操作难度较高,开展此项手术应具备5个方面条件:(1)较清晰的胸腔镜设备,(2)良好的术野显露,(3)熟练的镜下血管解剖分离技巧,(4)能将血管和支气管置入缝合切开器内,(5)纵隔淋巴结清扫技术.掌握正确的操作流程及一些关键技巧,可以缩短学习曲线.     

含双噁唑环的大环双内酯化合物FW-04-806发酵条件优化

目的对链霉菌FIM-04-806的次级代谢产物,含双噁唑环的大环双内酯化合物FW-04-806进行发酵条件研究。方法采用单因素试验进行培养基优化,探讨装液量、初始pH值等发酵参数的影响,同时逐级放大进行中试验证。结果确定了最佳培养条件:种子培养基为葡萄糖3%,蔗糖3%,玉米浆粉2%,CaCO3 0.75%,pH7.5;发酵培养基为可溶性淀粉3%,葡萄糖2%,黄豆粉1%,玉米浆粉2%,CaCO3 0.7%,pH7.5,接种量10%。优化后的摇瓶效价较初始水平提高了7倍以上,并在100L自动发酵罐及1.5吨发酵罐上得到验证。结论 FW-04-806优化的发酵条件为其工业化生产奠定了基础。     

蠕形螨ISSR-PCR的反应体系优化及引物筛选

目的以蠕形螨的DNA为模板,对蠕形螨简单重复序列锚定PCR(ISSR-PCR)反应体系优化并对ISSR引物进行筛选,为ISSR分析奠定基础。方法用自然沉降法收集山羊蠕形螨,用基因组DNA提取试剂盒提取山羊蠕形螨DNA,并以此为模板,以(CA)8RG(R为1分子的嘧啶)为引物,利用正交实验法,从Mg2+浓度、引物用量、dNTPs、DNA模板用量和TaqDNA聚合酶以及退火温度对蠕形螨ISSR-PCR反应体系进行优化,并以优化的反应体系筛选ISSR-PCR的引物。结果 ISSR-PCR 25μL最佳反应体系包括:0.4 mmol/L Mg2+、30 pmol引物、30～60 ng模板DNA、2u Taq酶,最佳退火温度为49℃、循环35次。筛选出10条条带清晰、多态性好、重复性高的引物。结论筛选出蠕形螨ISSR-PCR最佳反应体系和理想的引物,为蠕形螨的分子生物学研究奠定了基础。     

林荫银莲花不定芽增殖培养基的优化

为提高林荫银莲花(Anemone flaccida Fr.Schmidt)不定芽繁殖系数,对其组培快繁体系进行优化。以林荫银莲花无菌苗为外植体,研究了培养基中激素、碳源、添加物和矿质元素钙等组分对其不定芽增殖和生长状况的影响,得出最佳的不定芽增殖培养基配方。以1/2 Ca浓度MS为固体培养基,激素为1.0 mg/L 6-BA和1.0 mg/L NAA,蔗糖或食用白糖30 g/L,水解酪蛋白为添加物,浓度为750 mg/L,培养30 d后繁殖系数可达4.01,大幅提高了不定芽的增殖速度和质量,为工厂化生产林荫银莲花种苗奠定了基础。     

电子处方系统的设计与实现

随着门诊处方电子化的全面应用,住院处方同样面临电子化推广。本文通过对住院处方原有流程的分析,优化业务流程,对住院电子处方的软件设计说明,介绍住院电子处方的实现方法及主要功能、特点,并对设计中的问题进行补充。     

依托信息技术优化门诊流程

结合武警广东总队医院实践,介绍依托信息技术优化门诊流程的具体措施,包括提供全方位的自助服务、排队叫号系统、信息可视化服务等方面,从而有效提高门诊患者的就诊效率,增强患者满意度。     

黄芩指纹图谱的研究

目的：建立黄芩药材的HPLC指纹图谱,优化黄芩的提取方法和色谱条件,确定某些化学成分。方法：采用梯度洗脱方法进行色谱分离,AgilentTC-C18柱（4.6mm×250mm,5μm）,流动相：乙腈与0.1％冰醋酸溶液进行梯度洗脱,检测波长276nm,流速1.0ml／min,柱温25℃,使用标准品对其化学成分进行确定。结果：以水：乙醇：乙酸乙酯：冰醋酸（50：49：5：1）为提取溶剂,以乙腈与0.1％冰醋酸溶液进行梯度洗脱色谱峰分离效果较好并确定7种化学成分,优化了黄芩药材的HPLC指纹图谱。结论：本文建立的方法能较多的分离出色谱峰,可为黄芩药材的指纹图谱评价及物质基础的确定提供依据。