Effects of simplifying choice tasks on estimates of taste heterogeneity in stated-choice surveys

Researchers usually employ orthogonal arrays or D-optimal designs with little or no attribute overlap in stated-choice surveys. The challenge is to balance statistical efficiency and respondent burden to minimize the overall error in the survey responses. This study examined whether simplifying the choice task, by using a design with more overlap, provides advantages over standard minimum-overlap methods. We administered two designs for eliciting HIV test preferences to split samples. Surveys were undertaken at four HIV testing locations in San Francisco, California. Personal characteristics had different effects on willingness to pay for the two treatments, and gains in statistical efficiency in the minimal-overlap version more than compensated for possible imprecision from increased measurement error.     

应重视口腔颌面部恶性肿瘤的综合序列治疗

口腔颌面部恶性肿瘤约占全身恶性肿瘤的3％，虽然所占比例不高，但l大l其解剖部位特殊．涉及美观和重要的生理功能，冈此对患者机体和心理的影响不容忽视。早期（Ⅰ、Ⅱ期）口腔颌面部恶性肿瘤无论采用手术和（或）放射治疗，均能取得良好效果。但遗憾的是，大多数患者就诊时，已属局部一区域晚期（Ⅲ、Ⅳ期）。由于受到局部解剖和维持功能的限制，单纯通过扩大手术切除范围和改进现有手术技术，除能改善患者生存质量外，已无法提高此类患者的生存率，延长其生存时间。     

颈椎管哑铃形肿瘤的显微外科治疗

目的探讨不同入路显微手术切除颈椎管哑铃形肿瘤的手术方法,总结其主要优点和术后并发症情况。方法2004年5月至2006年7月共收治16例颈椎管哑铃形肿瘤,其中5例肿瘤最大径超过5cm。5例巨大肿瘤中4例位于上颈段,采用侧方改良的极外侧入路（后外侧肌间入路）, 1例外院手术复发的巨大肿瘤位于中颈段,采用分次后正中和前路联合切除并行后方和前方内固定加前方植骨融合;1例肿瘤椎管外部分向前方生长,采用颈前入路切除后行前方植骨融合加内固定,其余10例采用后正中入路,其中1例超过中线的肿瘤采用全椎板切除加椎管成形,7例半椎板切除, 1例复发肿瘤原路切除,1例未切除椎板切除肿瘤。结果手术全切肿瘤14例,次全切2例。所有病例术后症状均有明显改善,其中2例巨大肿瘤患者术后出现低氧血症,重新气管插管后逐渐恢复, 1例巨大肿瘤患者术后脑脊液漏皮下积液,经穿刺置管引流数日后恢复正常。其中12例随访9-18个月,无一例复发或出现脊柱不稳定的情况。结论对于颈椎管哑铃形肿瘤,应尽可能采用创伤小的手术方式,在切除肿瘤的同时,减少棘突、韧带、椎板以及小关节的破坏,减小创伤和对脊柱稳定性的破坏,预防脊柱后凸和侧凸畸形的发生。极外侧入路适用于微创切除体积较大的高颈段椎管哑铃形肿瘤,较小的肿瘤可以采用后正中入路半椎板开窗手术,对骨质破坏严重者需在切除肿瘤后行内固定手术。     

肌萎缩侧索硬化合并颈椎病的临床特点分析

目的:探讨肌萎缩侧索硬化ALS合并颈椎病患者的临床特征。方法:对75例ALS患者的临床资料进行回顾性分析,并对合并颈椎病的ALS患者与未合并颈椎病的ALS患者的临床特点进行比较。结果:合并颈椎病的ALS患者与未合并颈椎病的ALS患者的发病年龄、性别比例与临床特点差异均无统计学意义。结论:ALS可以并合颈椎病,颈椎病对ALS的发病年龄、临床特点无明显影响。     

颈椎病伴椎管狭窄患者再手术问题探讨

目的：探讨颈椎病伴椎管狭窄患者再手术的原因、手术方式及其相关问题。方法：我院2002年7月～2003年12月对40例颈椎病伴椎管狭窄术后疗效不佳或症状复发的患者进行了后路多节段（5个或以上）减压手术。根据其手术治疗方式及影像学资料分析再手术原因，并进行术后疗效评价。结果：经前路手术者再手术的主要原因为：（1）伴有多节段颈椎管狭窄因素时，只选择部分压迫重的节段行减压融合15例；（2）经前路多节段（≥3个节段）减压融合后，相邻节段继续退变，出现新的脊髓压迫表现及椎间不稳定9例；（3）伴有OPLL时，行部分节段前路减压融合后，病变呈进展表现，产生或加重对脊髓的压迫8例。经后路手术者再手术的原因为：（1）后路减压节段不够5例（包括1例前后路联合手术者）；（2）后路减压不充分3例。再手术后随访1．3～2．7年，平均2．1年，所有患者脊髓功能获得一定的提高，JOA评分改善率为51．3％。结论：颈椎病伴椎管狭窄病例再手术的主要原因为椎管狭窄因素仍然存在，经后路多节段（5个或以上）减压手术治疗可彻底去除颈椎管狭窄因素，有效解除脊髓前、后方所受的压迫，可获得较满意的临床疗效。     

经一侧半椎板入路显微手术切除椎管内神经鞘瘤

目的探讨经一侧半椎板入路在椎管内神经鞘瘤显微切除术中的应用。方法我们从1999年6月至2006年6月经一侧半椎板显微切除38例椎管内神经鞘瘤。其中肿瘤位于颈段13例，胸段19例，腰段6例。结果所有肿瘤均被全切除，病人术后2周即可下床活动，随访期内（2-48个月）患者的症状和体征均有明显改善，无手术并发症和脊柱畸形。结论经一侧半椎板入路能够最大程度保留脊柱后部的肌肉、韧带和骨结构，有利于脊柱的稳定性，具有手术创伤小、安全、卧床时间短等优点，值得进一步推广应用。     

改良Hardinge入路在非骨水泥全髋置换术中的应用

目的：对改良Hardinge入路行全髋置换进行评价。方法：对经改良Hardinge入路行非骨水泥全髋置换（THR－CL）术并获术后6个月以上随访的32例病人进行总结。结果：优良28例（88％），很好4例（12％），其中轻度跛行6例（19％），下肢不等长＞2cm1例（3％），改良Trendelenburg试验阳性3例（10％）。结论：此入路创伤小，暴露好，利于假体定位，易于控制下肢长度，术后外展肌功能恢复快。     

Anterior eye focusing of peripheral ultraviolet and visible radiation albedo

Concern about short- and long-term ultraviolet radiation (particularly UVB) damage to the eye has led to increased research in this area. Numerous studies have confirmed the pathogenic enhancing roles of reflected ultraviolet (UV) and visible radiation in our environment. There is concern that conventional sunglasses do not protect the eye adequately from reflected rays (albedo), especially on the lateral aspect, from behind and from below. Using eye models and computer ray tracing methods, the pathways of oblique rays incident at the temporal peripheral cornea have been plotted by Maloof, Ho and Coroneo.¹ These rays are refracted and focused and theoretically can result in up to 20 times the concentration of incident irradiance at the nasal anterior chamber angle and nasal equatorial cortex of the crystalline lens. The purpose of this study was to determine the limits of angular subtense of the incident peripheral light which is refracted in this manner in human subjects and to investigate the relation between corneal shape and certain ocular parameters to the limits. A statistically significant positive correlation was found between temporal entrance angle and anterior chamber depth (r = 0.70, P< 0.0006). The entrance angle ranged from 15 degrees to 30 degrees and was located 10 degrees to 45 degrees posterior to the coronal plane. Our results support Maloof and colleagues' predictions for the implication of focused peripheral UV and high intensity visible radiation in the pathogenesis of pterygium and cortical cataract and emphasise the need for lateral eye protection in conditions of high ultraviolet albedo.     

脑干区占位病变的手术入路

本文报告了1990年5月以来脑干区大型、复杂占位病变15例.其中,位于脑干内3例,脚间窝2例,岩尖部4例,全岩骨区1例,全斜坡区2例,第四脑室内3例.本组采用以扩大了的岩骨入路为主的联合入路,行肿瘤全切除8例,次全切除5例.2例仅作了活检加减压术.除1例死亡外,均恢复良好.本文结合文献,对脑干区手术入路进行了讨论.     

Enhanced stimulus-reward learning by intra-amygdala administration of a D3 dopamine receptor agonist

The amygdala is considered to be a critical neural substrate underlying the formation of stimulus-reward associations, and is known to receive substantial innervation from dopaminergic neurons located within the ventral mesencephalon. However, relat- ively little is known about the function of the mesoamygdaloid dopamine projection in stimulus-reward learning. Recently, we have found post-session intra-amygdala microinjections of d-amphetamine to enhance appetitive Pavlovian conditioning as assessed in a discriminative approach task. In the present study, we have examined the effects of dopamine receptor agonists possessing relative selectivity for the D₁, D₂ and D₃ receptor subtypes in order to examine more fully the role of the mesoamygdaloid dopamine projection in stimulus-reward learning. Thus, subjects were trained to associate an initially neutral stimulus (CS⁺) with 10% sucrose reward (US). A second, control stimulus (CS⁻) was also presented but never paired with sucrose reward. In order to measure specifically the conditioned response to CS⁺/CS⁻ presentation, responding during CS and US presentations was measured separately. Immediately following each training session, subjects received bilateral intra-amygdala infusion of 0.1, 1 or 10 nmol/side of SKF-38393, quinpirole or 7-OH-DPAT. Infusions of SKF-38393 or quinpirole were without effect on CS⁺ approach. However, post-session intra-amygdala infusions of 7-OH-DPAT enhanced selectively CS⁺ approach in a dose-dependent fashion. No dose of any drug affected CS⁻approach, US behaviours, or measures of extraneous behaviour. Subsequent acquisition of a novel conditioned instrumental response was also unaffected. Thus, the present data indicate a selective involvement of the D₃ dopamine receptor subtype in the modulation of stimulus-reward learning by the mesoamygdaloid dopamine projection. Received: 12 December 1996 / Final version: 9 April 1997