A laminar cortical model for 3D perception of slanted and curved surfaces and of 2D images: development, attention, and bistability

A model of laminar visual cortical dynamics proposes how 3D boundary and surface representations arise from viewing slanted and curved 3D objects and 2D images. The 3D boundary representations emerge from non-classical receptive field interactions within intracortical and intercortical feedback circuits. Such non-classical interactions within cortical areas V1 and V2 contextually disambiguate classical receptive field responses to ambiguous visual cues using cells that are sensitive to colinear contours, angles, and disparity gradients. Remarkably, these cell types can all be explained as variants of a unified perceptual grouping circuit whose most familiar example is a 2D colinear bipole cell. Model simulations show how this circuit can develop cell selectivity to colinear contours and angles, how slanted surfaces can activate 3D boundary representations that are sensitive to angles and disparity gradients, how 3D filling-in occurs across slanted surfaces, how a 2D Necker cube image can be represented in 3D, and how bistable 3D Necker cube percepts occur. The model also explains data about slant aftereffects and 3D neon color spreading. It shows how chemical transmitters that habituate, or depress, in an activity-dependent way can help to control development and also to trigger bistable 3D percepts and slant aftereffects. Attention can influence which of these percepts is perceived by propagating selectively along object boundaries.     

量化针刺手法对急性闭角型青光眼F值的影响

目的探讨量化针刺手法对急性闭角型青光眼的"临床前期"眼房水流量(F值)的影响(以下简称F值).方法对198例(204眼)随机分为观察与对照两组,观察针刺后3、6、12个月F值的临床效果,并对家兔眼房水进行针刺后的实验室生化分析.结果通过3个时段的效果分析,观察组效果显著(P＜0.05),且兔眼房水生化分析中离子浓度和渗透压均有明显改变.结论量化针刺手法对眼房水流量影响显著,是临床防治青光眼有效的方法之一.     

鼻咽清胶囊制备工艺研究

目的:系统研究鼻咽清胶囊的制备工艺。方法:通过正交设计实验,以收率为指标,优选在煎煮辛夷、黄芪和防风的过程中醇沉等工艺条件;并研究成型工艺中药粉的制备及休止角的测定。结果:煎煮工艺中提取物的平均收率为15.4%,确定选择玉米淀粉为辅料的成型工艺。结论:确定了鼻咽清胶囊制备过程中有关煎煮、成型工艺的最优参数条件。     

斜面导板在固定矫治下颌后缩型Ⅱ类1分类错中的作用

目的:评价固定矫治联合斜面导板治疗安氏Ⅱ类1分类错的效果。方法:选择处于生长发育末期的患儿22例,用固定矫治联合斜面导板,摄取矫治前后的头侧位片并作统计学分析。结果:联合斜面导板矫治后较好地减小前牙覆覆盖,使磨牙关系转变为中性。而且促进了下颌骨发育,对下切牙轴倾度控制较好,达到改善面型的目的。结论:恒牙列后期的安氏Ⅱ类1分类下颌后缩错采用固定矫治联合斜面导板可以取得较好的效果,并大大缩短疗程。     

Optimal Moving Angle of Pusher Plate in Occlusive‐Type Pulsatile Blood Pump

Since the occlusive‐type pulsatile extracorporeal blood pump (Twin‐Pulse Life Support System; Seoul National University, Seoul, Korea) received the CE mark of the European Directives and Korea Food and Drug Administration approval (2004) for short‐term applications as an extracorporeal life support system, the pump system has been tested for hemolysis. This pump system was recently upgraded with an ameliorated pusher plate to reduce hemolysis. In this study, numerical analysis and in vitro tests were performed to determine the optimal conditions for increasing the durability of the blood sac and pump output. During the simulation, the minimum sliding interface force (SIF) for the angle of the pusher plate movement (PPM) was calculated (40–70°). In the in vitro durability test, the angle of the PPM was increased gradually from 40 to 70° in 10° increments, and the mean time to failure (MTTF) of the blood sac was calculated. Fifteen tests were conducted for each case: 40, 50, 60, and 70° (n = 15 each). The MTTF of the blood sac was defined as the time when a crack of the blood sac occurred. The longer lifetime of the blood sac at 60° of the PPM (297.0 h) than that at 50° (197.6 h) was attributed to the lower SIF value (?0.13, normalized value) at 60° of the PPM.     

Mandibular third molars as a risk factor for angle fractures: a retrospective study

Introduction  

Anecdotal reports suggest that the presence of mandibular third molars predispose the mandible to angle fractures. The purpose of this study was to evaluate the presence of mandibular third molars as a risk factor for angle fractures in patients with fractured mandibles.     

Twin-block矫治器在安氏Ⅱ~1类错中的临床应用研究

目的观察Twin-block功能矫治器对于生长发育期安氏Ⅱ1类错的矫治作用,探讨其矫治机制。方法选择18例生长发育期的安氏Ⅱ1类错患者,男10例,女8例,年龄10¹3岁,无矫治史的患者使用Twin-block功能矫治器进行矫治。结果 18例患者经过2013岁,无矫治史的患者使用Twin-block功能矫治器进行矫治。结果 18例患者经过20²4个月的治疗后,前牙覆、覆盖关系基本正常,磨牙关系中性,软组织侧貌改善明显。结论 Twin-block功能矫治器对于生长发育期的安氏Ⅱ1类错患者效果明显。     

Mobilisation de l’angle colique gauche par cœlioscopie : technique opératoire

The clue of the mobilization of the splenic flexure is a complete division of the root of the transverse mesocolon along the pancreas. After the section of the terminal part of the inferior mesenteric vein, the retrogastric cavity is opened and the root of the mesocolon is cut from the right to the left onto the parieto-colic attachment. Thereafter the coloepiploic attachments are divided. The retromesocolic dissection is continued from top to bottom without opening the Gerota's fascia.     

以锁骨内侧端最高点为标志行右静脉角部穿刺的应用解剖

目的　研究以“颈锁等腰三角”为新标志的右静脉角穿刺的应用解剖。方法　将 74具成年尸体分为解剖观测组 (2 0具 )和尸体试穿组 (5 4具 )。以锁骨内侧端最高点 (P点 ,锁骨胸上结节 )为标志 ,向上作垂线 (N线 ) ,向外侧作水平线 (T线 ) ,沿锁骨向外上作斜线 (C线 ) ,通过局部解剖确定颈根部大血管与它们投影关系 ,进行了右静脉角部试穿 ,并测量其各项参数。结果　有 95 . 95 %的人 ,双侧锁骨内侧端存在明显的标志性突起即P点。 (2 )大多数人的右静脉角位于锁骨内侧端的稍上方。从右侧“颈锁等腰三角”底边的中、外 1/3交点 ,向锁骨胸上结节穿刺右静脉角部 ,是经颈根部大静脉置管的理想选择。只有不到一半的人 ,在解剖学上 ,存在着临床上作为穿刺标志的胸锁乳突肌三角。结论　以右侧锁骨内侧端最高点 (P点 )确立的“颈锁等腰三角” ,是右静脉角部穿刺的可靠标志