视场角设置对虚拟环境中目标判断的影响

目的探讨不同视场角参数对虚拟环境中目标判断的影响规律 ,找出最佳视场角参数。方法利用自行研制基于PC平台的虚拟现实 (VR)实验系统 ,选定 45名年龄在 2 3～ 5 8岁被试者并完成大小与角度判断的实验设计。首先进行 30 0人次的预实验 ,确定引起虚拟环境中目标判断差错的视场角及相应观察任务的差别等级 ,然后开始单因素、4水平的完全随机正式实验。结果方差分析表明 ,不同的虚拟环境视场角对目标判断的真实性有显著性影响 ,当视场角为 60°时 ,目标判断的正确率最大。结论利用VR技术进行载人航天器工效设计、操作训练或其它任务的研究时 ,应考虑视场角的作用 ,适合目标大小判断的视场角参数值宜取 60°,以便获得最大的工效     

Epidural hematoma following use of a three-point skull clamp.

We report an unusual case of epidural hematoma secondary to the use of a three-point skull-fixation device. Initially, a posterior-fossa brain tumor with hydrocephalus was diagnosed in a 15-year-old boy. Midline suboccipital craniectomy was performed with the patient placed in the prone position. A Mayfield (Ohio Medical Instrument Co., Cincinnati, OH, USA) skull clamp was used for fixation of the head during the surgical procedure, following which, a huge epidural hematoma developed within 6 hours of surgery, due to skull penetration and fracture at one of the clamp's pin sites located proximate to the coronal suture.     

宫颈癌合并妊娠的诊断及治疗进展

宫颈癌合并妊娠的发生率较低，但却是妊娠期最常见恶性肿瘤。妊娠期胎儿取舍问题的考虑会影响医患双方对宫颈癌治疗时间和治疗方案的选择，而宫颈癌也会影响到分娩方式的选择，从而影响围产儿的预后。近年来宫颈癌发病逐渐年轻化，如何处理两者的关系具有重要的临床意义。现综述近年来在宫颈癌合并妊娠的诊断及治疗等方面的研究进展。     

彩超引导介入治疗腘窝囊肿23例

目的探讨彩超引导下腘窝囊肿介入治疗的价值。方法在彩超引导下穿刺囊肿并抽尽囊液，生理盐水反复冲洗囊腔后注入无水乙醇，5min后抽出，反复2～3次。结果23例中22例穿刺一次治愈，1例穿刺2次治愈。23例随访6个月，无复发。结论彩超引导下介入治疗腘窝囊肿操作简便，创伤轻微，安全可靠，效果显著，可重复操作。     

甲壳素涂层PGLA神经导管修复兔面神经缺损的实验研究

目的:探讨甲壳素涂层PGLA神经导管修复兔面神经缺损的效果。方法:成年雄性新西兰兔24只,无菌条件下切断双侧面神经下颊支,制成15mm的兔面神经下颊支缺损模型。左侧用甲壳素涂层聚丙交脂-乙交脂共聚物[poly(L-lactide-co-glycolide),PGLA]神经导管修复;右侧用翻转自体神经修复作为对照。术后5周、10周和14周行大体观察、电生理检查、组织学、电镜观察评价修复效果。结果:术后5周观察到神经导管中有新生轴索通过,再生神经发育不成熟;右侧自体神经修复近段有髓神经纤维均匀疏散分布,远段未见明显再生神经束形成。术后14周左侧再生神经已通过神经导管长入远端,电生理检查结果表明自体神经修复侧再生神经质量优于神经导管修复侧,差异有统计学意义(P<0.01)。自体神经修复再生纤维密度优于神经导管修复侧,差异有统计学意义(P<0.01),但自体神经修复侧近段神经髓鞘部分空泡样变性及脱髓鞘改变,远段再生神经纤维束形成少,面肌联带运动程度较导管修复侧严重。结论:甲壳素涂层PGLA神经导管能有效修复周围神经缺损,有望替代自体神经移植。     

Paracentral Corneal Dellen： A Rare Sign of Graves Ophthalmopathy

Purpose:To report a rare sign, paracentral corneal dellen that developed in a middleaged female patient with Graves ophthalmopathy.Methods:A paracentral corneal dellen developed in the left eye in a 42-year-old woman who was diagnosed as Graves ophthalmopathy. The patient had remarkable upper eyelid retraction, upper eyelid lag and upward motility restriction. The Graves ophthalmopathy was classified as Grade Ⅳ according to NOSPECS classification.Results:Local artificial tear film and 0.3％ Tobramycin eye drops were administered to both eyes.Twenty-four hours later, the left corneal dellen disappeared.Conclusions:Graves ophthalmopathy can lead to paracentral corneal dellen because of severe upper eyelid retraction and upward motility restriction of the eye in spite of the lack of lagophthalmos. Artificial tear drop and antibiotic eye drop therapy helped even though the patient did not have corneal exposure. Eye Science 2003;19:174-175.     

特发性震颤的临床特点分析

目的探讨特发性震颤（essential tremor,ET）的临床特点。方法回顾性分析98例ET患者的临床资料。结果98例ET中男56例,女42例。发病年龄6～72岁,平均43．08±18．18岁。病程1～48年,平均14．04±11．39年。48例（48．98％）患者有阳性家族史。临床主要表现为单症状的姿势性震颤,累及部位依次为手98例（100％）、头38例（38．78％）、下肢28例（28．57％）、咽喉部16例（16．33％）、下颏10例（10．20％）等。64例患者做了饮酒试验,其中58例（90．63％）有酒精反应。84．62％的患者服用盐酸阿罗洛尔治疗有效。结论特发性震颤的临床表现以单症状姿势性震颤为主,手及头部受累明显,多数患者对酒精有反应,盐酸阿罗洛尔治疗有效。     

小剂量长春新碱对小鼠M1细胞的分化诱导作用研究

目的：利用培养小鼠髓性白血病（M1细胞）来检测小剂长春新碱（VCR）对小鼠M1细胞分化诱导功能。方法：分观察组对照组，观察组使用VCR1次5ug后进行吞噬功能实验，及对细胞形态的观察与空白对照组比较。结果：发现使用小剂量长春新碱后小鼠M1细胞诱变细胞增多，吴噬功能增强，结论：说明小剂量长春新碱对培养小鼠M1细胞有一定诱导功能，诱导其向粒细胞、吞噬细胞方向转化，在临床上白血病的治疗有一定的作用。     

Repositioning of the gingival margin by extrusion.

In this case report, orthodontic intervention was used to move the gingival margin of a maxillary canine incisally by almost 9 mm to mimic a lateral incisor. Increasing the thickness of the labial plate of bone of the canine and subsequently increasing the thickness of the attached gingiva before extrusion prevented gingival recession at a later stage. In many situations, orthodontic treatment can achieve results that could not be attained by restorations and other means of cosmetic dentistry, especially when dealing with gingival margins and gingival height. A step-by-step approach to achieving these treatment objectives is described.     

NADPH-Diaphorase-Positive Neurons in Primate Cerebral Cortex Colocalize with GABA and Calcium-Binding Proteins

Neurons in the monkey cerebral cortex containing nicotinamideadenine dinucleotide phosphate-diaphorase (NADPH-d) can he dividedinto two distinct types, both nonpyramidal. Type I neurons havea large soma (diameter 20–50 µm), a dense NADPH-dhistochemical reaction. and are distributed throughout the cortex,but mainly in the subcortical white matter, and are mostly aspiny.Type II cells have a small soma (< 20 µm) with lightNADPH-d reactivity and are distributed primarily in the supragranularlayers, particularly layers II and upper III. The numericaldensity of type II cells is much greater than that of type I.Type I neurons also stain for GABA and a few intracortical typeI cells contain calbindin. All type II cells found here arecolocalized with both GABA and calbindin. Neither type I nortype II cells are stained for parvalbumin. Together with previous observations that almost all corticalNADPH-d cells in various subprimates are like type I cells,we suggest that type II cells may form a group of NADPH-d-richneurons differentiated in higher mammalian cortex from a subpopulationof calbindin-containing GABAergic interneurons, and these nitricoxide-synthesizing cells may play a role in control of intracorticalneuronal activity characteristic of higher cerebral functionsin advanced mammals.