Isokinetic quadriceps symmetry helps in the decision to return to running after anterior cruciate ligament reconstruction

BackgroundAfter anterior cruciate ligament reconstruction (ACLR), the decision to allow a return to running is empirical, and the post-operative delay is the most-used criterion. The Quadriceps isokinetic-strength Limb Symmetry Index (Quadriceps LSI), with a cutoff of 60%, could be a useful criterion.ObjectiveTo determine the association between a Quadriceps LSI ≥ 60% and return to running after ACLR.MethodsOver a 10-year period, we retrospectively included 470 patients who underwent ACLR. Four months after ACLR, participants performed an isokinetic test; quadriceps concentric peak torque was used to calculate the Quadriceps LSI at 60?/s. With a Quadriceps LSI ≥ 60%, a return to running was suggested. At 6 months after ACLR, participants were clinically evaluated for a return to sport and post-operative middle-term complications. A multivariable predictive model was built to assess the efficiency diagnosis of this cutoff in order to consider cofounding factors. Quadriceps LSI cutoff ≥ 60% was assessed with sensitivity, specificity and the area under the receiver operating characteristic curve (AUC).ResultsAccording to our decision-making process with the 60% Quadriceps LSI cutoff at 60?/s, 285 patients were authorized to return to running at 4 months after ACLR and 185 were not, but 21% (n = 59) and 24% (n = 45), respectively, were not compliant with the recommendation. No iterative autograft rupture or meniscus pathology occurred at 6 months of follow-up. On multivariable logistic regression analysis, a return to running by using the 60% Quadriceps LSI cutoff was associated with undergoing the hamstring strand procedure (odds ratio 2.60, 95% confidence interval [CI] 1.75–3.84; P < 0.0001) and the absence of knee complications (1.18, 1.07–1.29; P = 0.001) at 4 months. The sensitivity and specificity of the 60% Quadriceps LSI cutoff were 83% and 70%, respectively. The AUC was 0.840 (95% CI 0.803–0.877).ConclusionsUsing the 60% cutoff of the isokinetic Quadriceps LSI at 4 months after ACLR could help in the decision to allow a return to running.     

Symmetric patterns with different luminance polarity (anti‐symmetry) generate an automatic response in extrastriate cortex

People can quickly detect bilateral reflection in an image. This is true when elements of the same luminance are matched on either side of the axis (symmetry) and when they have opposite luminance polarity (anti‐symmetry). Using electroencephalography, we measured the well‐established sustained posterior negativity (SPN) response to symmetry and anti‐symmetry. In one task, participants judged the presence or absence of regularity (Regularity Discrimination Task). In another, they judged the presence or absence of rare colored oddball trials (Colored Oddball Task). Previous work has concluded that anti‐symmetry is only detected indirectly, through serial visual search of element locations. This selective attention account predicts that the anti‐symmetry SPN should be abolished in the Colored Oddball Task because there is no need to search for anti‐symmetry. However, this prediction was not confirmed: The symmetry and anti‐symmetry SPN waves were not modulated by task. We conclude that at least some forms of anti‐symmetry can be extracted from the image automatically, in much the same way as symmetry. This is an important consideration for models of symmetry perception, which must be flexible enough to accommodate opposite luminance polarity, while also accounting for the fact anti‐symmetry is often perceptually weaker than symmetry.     

Three‐dimensional analysis of shape variations and symmetry of the fibula,tibia, calcaneus and talus

The bones forming the talocrural joint (TCJ) and subtalar joint (STJ) are often assumed to be bilaterally symmetric. Therefore, the contralateral limb (i.e. the fibula, tibia, calcaneus and talus) is used as a template or an intra‐subject control in clinical and research practice. However, the validity of the symmetry assumption is controversial, because insufficient information is available on the shape variations and bilateral (a)symmetry of the fibula, tibia, calcaneus and talus. Using three‐dimensional spatially dense sampled representations of bone shapes extracted from bilateral computed tomography scans of 66 individuals (55 male, mean age: 61 ± 10 years; 11 female, mean age: 53 ± 15 years), we analyzed whether: (i) similar shape patterns exist in the left and right bones of the same type; (ii) gender has an effect on bone shape variations; (iii) intra‐subject shape variation is smaller than that of inter‐subject for a given shape variance direction. For the first set of analyses, all left and right instances of the same type of bone were considered as two separate groups, and statistically compared with each other on multiple aspects including group location (central tendency), variance‐covariance scale (dispersion) and orientation (covariance structure) using distance‐based permutational tests. For the second and third sets of analyses, all left and right bones of the same type were pooled into one group, and shape variations in the TCJ and STJ bones were extracted using principal component analysis. The effects of gender on age‐adjusted bone shape differences were assessed using an analysis of covariance. Moreover, intra‐class correlation was employed to evaluate intra‐ and inter‐subject bone shape variations. For each bone type, both sides had similar shape patterns (P_{permutational}‐values > 0.05). After Bonferroni adjustment, gender led to shape differences, which were mainly in the lateral and medial condyles of the tibia (P = 0.003), the length and height of the calcaneus (P < 0.001), the posterior and anterior talar articular surfaces of the calcaneus (P = 0.001), and in the posterior aspect of the talus (P = 0.001). Intra‐subject shape variations in the tibial tuberosity together with the diameter of the tibia, and the curvature of the fibula shaft and the diameter of the fibula were as high as those of inter‐subject. This result suggests that the shape symmetry assumption could be violated for some specific shape variations in the fibula and tibia.     

唇裂术后鼻部对称性的变化及其影响因素

目的 评价华西法修复单侧完全性唇裂术后鼻底宽度及其对称性的变化以及与裂隙宽度的关系,为一期手术鼻畸形整复提供参考.方法选择应用华西法修复单侧完全性唇裂患者27例,分别于术前、术后1周及术后1年拍摄面部正位照片,测量鼻小柱中点偏离程度、鼻底宽度及裂隙宽度,计算鼻小柱中点回归率、鼻底宽度对称率和鼻底宽度变化,并采用SPSS...     

球面对称设计结合遗传神经网络优选黄芪-红花药对水提工艺

目的采用球面对称设计及遗传神经网络优选黄芪-红花药对的水提工艺。方法将黄芪-红花药对水提液中8种有效成分(羟基红花黄色素A、紫丁香苷、毛蕊异黄酮苷、脱水红花黄色素B、山柰酚-3-O-芸香糖苷、芒柄花苷、毛蕊异黄酮、黄芪甲苷)的含量进行赋权,以计算得到的综合得分作为水提工艺的评价指标。在单因素实验基础上,选择液料比、提取时间、提取温度3个因素,依据球面对称设计进行实验,并结合遗传神经网络模型进一步优选黄芪-红花药对水提工艺参数。结果球面对称设计得到的最佳提取条件为液料比20∶1、提取时间30 min、提取温度87℃、提取次数2次,其综合评分为4.877;以遗传神经网络得到的最佳提取条件为液料比22.7∶1、提取时间30 min、提取温度87℃、提取次数2次,经验证该条件下的综合得分为5.004。实验结果显示,遗传神经网络能够提高水提工艺条件的综合评分。结论球面对称设计和遗传神经网络能够优化黄芪-红花药对水提工艺参数,可为中药及其制剂中多种有效成分提取的工艺优选提供参考。     

术前鼻模结合手术矫正单侧不完全性唇裂鼻畸形的临床研究

目的：评价采用术前鼻模矫治（PNM）结合唇裂手术初期鼻矫正术治疗单侧不完全性唇裂的临床效果。方法：35例行 PNM单侧不完全唇裂患儿为治疗组;对照组35例未行术前治疗。在矫正前（T0）、唇裂术前（T1）、术后1周（T2）、术后1月（T3）、术后1年（T4）分别拍摄鼻部照片,测量分析鼻孔高度、鼻孔宽度、鼻小柱倾斜度的对称性的变化。结果：T0-T1、T1-T2,患者的鼻孔高度、鼻孔宽度和鼻小柱偏斜度明显改善（P ＜0．05）,在 T2-T3与 T3-T4,改善程度差异无统计学意义（P ＞0．05）。结论：PNM结合唇裂手术初期修复鼻畸形可明显改善鼻部对称性,提高单侧不完全性唇裂鼻畸形的治疗效果。     

Adaptive self‐organization in the embryo: its importance to adult anatomy and to tissue engineering

The anatomy of healthy humans shows much minor variation, and twin‐studies reveal at least some of this variation cannot be explained genetically. A plausible explanation is that fine‐scale anatomy is not specified directly in a genetic programme, but emerges from self‐organizing behaviours of cells that, for example, place a new capillary where it happens to be needed to prevent local hypoxia. Self‐organizing behaviour can be identified by manipulating growing tissues (e.g. putting them under a spatial constraint) and observing an adaptive change that conserves the character of the normal tissue while altering its precise anatomy. Self‐organization can be practically useful in tissue engineering but it is limited; generally, it is good for producing realistic small‐scale anatomy but large‐scale features will be missing. This is because self‐organizing organoids miss critical symmetry‐breaking influences present in the embryo: simulating these artificially, for example, with local signal sources, makes anatomy realistic even at large scales. A growing understanding of the mechanisms of self‐organization is now allowing synthetic biologists to take their first tentative steps towards constructing artificial multicellular systems that spontaneously organize themselves into patterns, which may soon be extended into three‐dimensional shapes.