Provider networks and primary‐care signups: do they restrict the use of medical services?

This article analyzes the effect of gatekeeper and network restrictions on use of health‐care services using simulation‐based estimation methods. Data from the Community Tracking Survey (1996–1997) show significant evidence of selection into plans with gatekeeper and/or network restrictions. Enrollees in plans with networks of physicians have fewer office‐based visits to non‐physician medical professionals, but more emergency room visits and hospital stays. Individuals in plans that require signups with a primary‐care provider have more visits to non‐physician providers of care, more surgeries and hospital stays but substantially fewer emergency room visits. Enrollees of plans that do not pay for out‐of‐network services have more office‐based and emergency room visits, but less surgeries and hospitalizations. Copyright © 2008 John Wiley & Sons, Ltd.     

Computer‐simulated bi‐directional alveolar distraction osteogenesis

Objectives: Computer‐based surgical planning allows surgeons to evaluate bone morphology in three dimensions and to perform accurate virtual surgery preoperatively. This study was performed to evaluate the feasibility of using preoperative surgical simulation to enhance the clinical outcome in patients undergoing bi‐directional alveolar distraction osteogenesis. Material and methods: Nine patients (mean age, 49 years; range, 20–61 years) with maxillary segmental alveolar defects following post‐traumatic atrophy or disuse atrophy after periodontal tooth loss were enrolled in the study. All patients were scheduled for implant placement. Three‐dimensional (3‐D) morphological evaluation and virtual bi‐directional distraction were performed with SimPlant CMF/OMS surgical simulation software (Materialise). In addition, use of an extraosseous bi‐directional distraction device (V2‐Alveolar Distraction System; Medartis AG) was evaluated during the 3‐D alveolar regeneration simulation and resulting augmentation. Results: Alveolar height regeneration and labial‐buccal augmentation were planned preoperatively using surgical simulation software. New bone formation with sufficient vertical augmentation of 5.8 mm was observed. As we encountered strong palatal inclination, the angulation required for labial‐buccal augmentation during active distraction was the maximum angulation of 40°, even greater than that required in the preoperative simulation of 23.9°. Furthermore, the labial‐buccal augmented angulation was gradually decreased to 11.2° at the time of implant placement. In all cases, implantation was successful at the well‐augmented sites, with sufficient primary stability after a 3‐month consolidation period. Conclusions: Preoperative 3‐D simulation is a potentially valuable tool for treatment of the morphologically complicated oral‐maxillofacial region. More realistic surgical simulations are anticipated with ongoing effort to collect and integrate clinical data into next‐generation software.     

O139霍乱弧菌在模拟水中自发L型变异及其意义探讨

目的：探讨O139霍乱弧菌在水中自发变异为L型菌的情况；方法：采用消毒模拟水样长期观察，定期培养，检查L型菌及原菌。结果：多次从模拟水中检出L型菌,但检出频率与不同水体、不同环境温度有关。结论：O139霍乱弧菌在水中可自发变异成L型菌，且与该菌在水体中的存活时间长短有关。     

一种选择照射弧的自动优化算法

提出剂量斥力、剂量引力的概念 ,并给出了计算公式。对X刀治疗计划设计中照射弧的选择问题建立了有约束优化的数学模型 ,提出了在缩减的相空间内依据斥力场和引力场分布 ,采用模拟退火算法自动选择最优照射弧组合的实现方案     

分阶段多准则立体定向放射治疗计划研究

立体定向放射治疗计划是X-刀放射治疗的重要组成部分。提出了一种分阶段多准则立体定向放射治疗计划理论，将优化过程分三个阶段。第一阶段利用线性规划法缩小解空间；第二阶段采用复形调优法以获得肿瘤区均匀且高的剂量分布；第三阶段采用有约束模拟退火法以获得符合临床实际的治疗效果。与三个优化阶段相对应的三个优化准则分别为：最大化肿瘤区与周围正常组织的积分剂量之差、肿瘤体积内均匀的剂量分布和基于放射生物学效应、符合临床实际的放射治疗统计模型、文中的实验结果也证实了上述理论的正确性。     

电子模拟人优化心脏听诊教学的探讨

Objective To explore the assistant teaching effects with electronic simulated patients in the heart auscultation teaching. Methods 106 students were divided into the electronic simulated patient teaching group (experimental group ) and the traditional method teaching group (control group ) at random. Through the questionnaire survey, the written examination and the practice skill inspection form,we compared the students' learning situation of the two groups. Results There was no significant differ-ence in the written examination results between the two group students ( P ＞ 0.05 ); the practice skill in-spection results of the experimental group was obviously higher than those of the control group, there being significant difference ( P ＜ 0.05 ). The questionnaire survey about teaching satisfaction degree with electronic simulated patients showd that 77.36% of the students appraiseot for good, 18.87% for general,3.77% for poor. Conclusions The assistant teaching with electronic simulated patients was helpful in improving students' practice operation skills. It had many merits, such as comprehensive contents, directviewing and strong repeatability, which might optimize the heart auscultation teaching.     

造纸厂热能负荷动态优化调度

建立了造纸厂能耗大的间隙式设备蒸球的动态优化调度模型，对该模型运用隐枚举（ＩＥ）算法和扩充了接收新解准则的模拟退火（ＳＡ）算法，分别进行了求解，最后从给出的仿真结果证明了该模型和算法的有效性．     

模拟跳伞着陆冲击力与冲击时间的关系

在实验室模拟条件下,研究着陆冲击力与着陆冲击时间的关系。被试者为3名年轻健康的男伞兵。当其负荷26.5k或无负荷,分别从1.0,1.5和2.0m的平台上跳下时,用高速摄影法记录他们身上的标记。计算结果表明:(1)作用在各活动节段上的着陆冲击力,随着陆冲击时间的延长而减少,作用在足部的着陆冲击力峰值与着陆冲击时间亦有相同的关系;(2)着陆冲击时间为0.08～O.26s时,上述诸力与其在0.08s时的值相比,减少40.6～64.1％;(3)作用在足部的着陆冲击力峰值与着陆冲击时间的关系曲线,与其回归方程的曲线相比,非常接近。     

Articulated Thoughts About Antigay Hate Crimes

This study employed the articulated thoughts in simulated situations (ATSS) paradigm in the investigation of college students' thoughts upon confrontation with a conspiracy to commit a sexual-orientation-based hate crime versus a nonbias crime. In a between-subjects experimental design, participants were exposed to an audiotaped scenario depicting either the planning of a hate crime or a comparable nonhate crime. Content analysis of participants' articulated thoughts in response to these stimuli revealed that the hate crime resulted in more intentions to physically aggress against the perpetrator. This supports the notion that hate crimes have a greater potential than other crimes to lead to future violence. More people were also willing to intervene and help the hate crime victim than the nonhate crime victim. In addition, antigay attitudes turned out to be predictive of anger against the hate crime victim, disapproval of the hate crime victim, and support of the hate crime perpetrators. Implications of these findings, as well as suggestions for future research, are discussed.