Bilateral field advantage in visual crowding

Thirty randomly oriented T’s were presented in a circle around fixation at an eccentricity of 11° such that each T was crowded by its neighbors. Two locations within the same hemifield (unilateral condition) or one location in each hemifield (bilateral condition) were precued for subsequent probing. Observers were then asked to report the orientation of a target T at one of these locations. A bilateral field advantage was found: target identification was better when the two precued targets were in different hemifields than when they were within the same hemifield. This bilateral advantage was absent when only targets were presented, without any distracters. Further controls showed that this advantage could not be attributed to differences between horizontal and vertical target alignments or to visual field anisotropies. A similar bilateral advantage has been reported for multiple object tracking (Alvarez, G. A., & Cavanagh, P. (2005). Independent resources for attentional tracking in the left and right visual fields. Psychological Science 16(8), 637-643) and other attentional tasks. Our results suggest that crowding also demonstrates separate attentional resources in the left and right hemifields. There was a cost to attending to two targets presented unilaterally over attending to a single target. However, this cost was reduced when the two crowded targets were in separate hemifields.     

Effects of Crowding on the Thermal Stability of Heterogeneous Protein Solutions

Crowding can substantially affect the transition of a protein between its native (N) and unfolded (U) states via volume exclusion effects. Also, it influences considerably the aggregation (A) of unfolded proteins. To examine the details, we developed an approach for computing the kinetic rates of the process N ↔ U → A in which the concentration of the protein is explicitly taken into account. We then compute the relative change with temperature of the protein denaturation for various fractional volume occupancies and partition of proteins in solution. The analysis indicates that, in protein solutions in which the average distance between proteins is comparable with the radius of gyration of an unfolded protein, steric effects increase the stability of the proteins which are in compact, native states. In heterogeneous protein solutions containing various types of proteins with different thermal stabilities, the unfolding of the most thermolabile proteins will increase the stability of the other proteins. The results shed light on the way proteins change the thermal stability of a cell as they unfold and aggregate. This study may be valuable in questions related to the dynamics of thermal injuries.     

Impact of revised triage to improve throughput in an ED with limited traditional fast track population

Background

Emergency department (ED) crowding is associated with patient safety concerns, increased patients left without being seen (LWBS), low patient satisfaction, and lost ED revenue. The objective was to measure the impact of a revised triage process on ED throughput.

铸造式扩弓器治疗安氏Ⅰ类牙列拥挤的临床研究

目的探讨使用铸造式扩弓器非拔牙矫治安氏Ⅰ类错(?)伴轻中度牙列拥挤病例的临床疗效,为临床应用提供依据。方法选取32例安氏Ⅰ类错(?)畸形伴轻中度牙列拥挤病例。其中17例采用铸造式上颌扩弓配合固定矫治技术进行非拔牙正畸治疗(实验组);15例仅采取非拔牙的固定矫治(对照组)。分别在T1(正畸治疗前)、T2(正畸治疗结束)拍摄头颅侧位定位片并测量分析。结果头影测量分析显示两组间下颌平面角及前面高的增加无统计学差异(P>0.05)。对照组上前牙明显较扩弓组唇倾(P<0.05),下前牙唇倾量均有增加(扩弓组=4.05°,对照组=7.16°,P>0.05)。扩弓组上、下前牙突距(U1-NA和L1-NB)变化量更小(P<0.05)。两组间上颌磨牙垂直高度的变化无显著性差异。结论铸造式扩弓器在扩宽牙弓解除拥挤的同时,能有效地控制磨牙高度及面下1/3高度的变化。     

Creating a Rapid Assessment Zone with Limited Emergency Department Capacity Decreases Patients Leaving Without Being Seen: A Quality Improvement Initiative

IntroductionPatients leaving the emergency department before treatment (left without being seen) result in increased risks to patients and loss of revenue to the hospital system. Rapid assessment zones, where patients can be quickly evaluated and treated, have the potential to improve ED throughput and decrease the rates of patients leaving without being seen. We sought to evaluate the impact of a rapid assessment zone on the rate of patients leaving without being seen.MethodsA pre- and post-quality improvement process was performed to examine the impact of implementing a rapid assessment zone process at an urban community hospital emergency department. Through a structured, multidisciplinary approach using the Plan, Do, Check, Act Deming Cycle of process improvement, the triage area was redesigned to include 8 rapid assessment rooms and shifted additional ED staff, including nurses and providers, into this space. Rates of patients who left without being seen, median arrival to provider times, and discharge length of stay between the pre- and postintervention periods were compared using parametric and nonparametric tests when appropriate.ResultsImplementation of the rapid assessment zone occurred February 1, 2021, with 42,115 ED visits eligible for analysis; 20,731 visits before implementation and 21,384 visits after implementation. All metrics improved from the 6 months before intervention to the 6 month after intervention: rate of patients who left without being seen (5.64% vs 2.55%; c² = 258.13; P < .01), median arrival to provider time in minutes (28 vs 11; P < .01), and median discharge length of stay in minutes (205 vs 163; P < .01).DiscussionThrough collaboration and an interdisciplinary team approach, leaders and staff developed and implemented a rapid assessment zone that reduced multiple throughput metrics.     

上颌唇挡早期矫治引起的牙弓三维变化分析

目的 研究唇挡早期矫治上颌拥挤病例引起的牙弓三维改变.方法 选取正畸患者12例,平均年龄9.8岁.为缓解上颌的拥挤,戴用唇挡8个月.戴用唇挡前后取记存模型,进行三维数字化,以第三腭皱为参考将治疗前后的模型重叠,分析牙齿三维位置改变及倾斜度的变化.配对t检验比较治疗前后牙弓宽度和上牙弓弧形长度的差异.结果 戴用唇挡后,牙齿三维方向的改变以后部牙弓的变化最为显著,矢状向上颌第一前磨牙、第一磨牙分别远中移动2.08、2.03mm,上牙弓弧形长度增加5.12mm;垂直向上颌第一前磨牙升高1.17mm,第一磨牙升高0.72mm;横向上颌第一前磨牙间宽度增加2.62mm,第一磨牙间宽度增加3.08mm;以上各测量均有统计学意义(P＜0.05).同时上颌切牙存在少量前移、扩宽和唇倾.上颌切牙唇倾度增加3.90°,第一磨牙远中倾斜度增加8.23,有显著性差异(P＜0.05).结论 上颌唇挡可以缓解轻中度的牙弓拥挤.唇挡引起的牙弓长度增加主要是由于磨牙的远中移动、后倾以及牙弓的扩宽.     

CBCT of skeletal changes following rapid maxillary expansion to increase arch-length with a development-dependent bonded or banded appliance

Objective:To assess the three-dimensional (3D) skeletal response to a standardized 5 mm of rapid maxillary expansion (RME) in growing children (6–15 years) with maxillary width deficiency and crowding.Materials and Methods:A bonded appliance was used prior to the eruption of the maxillary first premolars (Mx4s), and a banded appliance was used thereafter. A consecutive sample of 89 patients (29 boys and 60 girls) from a large pediatric dentistry and orthodontics practice was divided into four groups: 1) 6–8 years old (n  =  26), 2) 9–11 years old with unerupted Mx4s (n  =  21), 3) 9–11 years with erupted Mx4s (n  =  23), and 4) 12–15 years (n  =  19). For all patients, the 3D evaluation of dental and skeletal effects was performed with cone-beam computed tomography (CBCT).Results:For both appliances in all patients, CBCT confirmed a triangular pattern of expansion in both the frontal and sagittal planes. Overall, both appliances produced significant maxillary expansion (>80% of the 5-mm activation), but older children showed a progressively more dental (less skeletal) response. Comparison of the two types of expanders in the crossover sample, children aged 9–11 years, showed that the bonded RME produced the most efficient skeletal expansion in the preadolescent sample. Increased maxillary width at the level of the zygomaticomaxillary suture was the best indicator for development of maxillary arch circumference.Conclusion:Development-dependent appliances (bonded RPE before Mx4s erupt, and a banded device thereafter) provided optimal RME treatment for all children from age 6–15 years.     

Local and non-local deficits in amblyopia: acuity and spatial interactions

Amblyopic vision is thought to be limited by abnormal long-range spatial interactions, but their exact mode of action and relationship to the main amblyopic deficit in visual acuity is largely unknown. We studied this relationship in a group (N=59) of anisometropic (N=21) and strabismic (or combined, N=38) subjects, using (1) a single and multi-pattern (crowded) computerized static Tumbling-E test with scaled spacing of two pattern widths (TeVA), in addition to an optotype (ETDRS chart) acuity test (VA) and (2) contrast detection of Gabor patches with lateral flankers (lateral masking) along the horizontal and vertical axes as well as in collinear and parallel configurations. By correlating the different measures of visual acuity and contrast suppression, we found that (1) the VA of the strabismic subjects could be decomposed into two uncorrelated components measured in TeVA: acuity for isolated patterns and acuity reduction due to flanking patterns. The latter comprised over 60% of the VA magnitude, on the average and accounted for over 50% of its variance. In contrast, a slight reduction in acuity was found in the anisometropic subjects, and the acuity for a single pattern could account for 70% of the VA variance. (2) The lateral suppression (contrast threshold elevation) in a parallel configuration along the horizontal axis was correlated with the VA (R2=0.7), as well as with the crowding effect (TeVA elevation, R2=0.5) for the strabismic group. Some correlation with the VA was also found for the collinear configuration in the anisometropic group, but less suppression and no correlation were found for all the vertical configurations in all the groups. The results indicate the existence of a specific non-local component of the strabismic deficit, in addition to the local acuity deficit in all amblyopia types. This deficit might reflect long-range lateral inhibition, or alternatively, an inaccurate and scattered top-down attentional selection mechanism.