symmetry

对称性
  • 文章类型: Journal Article
    花器官的发育,对于在高等植物中建立花的对称性和形态至关重要,受MADS-box基因调控。在向日葵,头状花序由射线和圆盘小花组成,具有各种花器官。在向日葵长花瓣突变体(lpm)中,异常的圆盘状(射线状)小花具有延长的花瓣和退化的雄蕊,导致从同构对称到辐射对称的转变。在这项研究中,我们研究了MADS-box基因对花器官的影响,特别是在花瓣上,使用WT和LPM植物作为材料。根据我们的RNA-seq数据,确定了29个MADS-box候选基因,以及它们在花器官发育中的作用,尤其是花瓣,被探索,通过RNA测序和qPCR分析WT和lpm植物中各种组织的表达水平。结果表明,HaMADS3,HaMADS7和HaMADS8可以调节向日葵花瓣的发育。高水平的HaMADS3缓解了对细胞增殖的抑制,与低水平的HaMADS7和HaMADS8一起,促进了花瓣的延长并保持了射线小花的形态。相比之下,低水平的HaMADS3和高水平的HaMADS7和HaMADS8抑制了花瓣的延伸并维持了椎间盘小花的形态。它们的协调可能有助于向日葵中圆盘和射线小花的分化,并保持吸引传粉者和产生后代之间的平衡。同时,花瓣长度和MADS-box基因表达水平之间的Pearson相关性分析进一步表明它们参与花瓣延长。此外,对顺式作用元件的分析表明,这三个MADS-box基因可能通过调节HaCYC2c的表达活性来调节花瓣发育和花对称性的建立。我们的发现可以为花瓣发育和花形态形成的分子调控网络提供一些新的认识。以及向日葵中圆盘和光线小花的分化。
    The development of floral organs, crucial for the establishment of floral symmetry and morphology in higher plants, is regulated by MADS-box genes. In sunflower, the capitulum is comprised of ray and disc florets with various floral organs. In the sunflower long petal mutant (lpm), the abnormal disc (ray-like) floret possesses prolongated petals and degenerated stamens, resulting in a transformation from zygomorphic to actinomorphic symmetry. In this study, we investigated the effect of MADS-box genes on floral organs, particularly on petals, using WT and lpm plants as materials. Based on our RNA-seq data, 29 MADS-box candidate genes were identified, and their roles on floral organ development, especially in petals, were explored, by analyzing the expression levels in various tissues in WT and lpm plants through RNA-sequencing and qPCR. The results suggested that HaMADS3, HaMADS7, and HaMADS8 could regulate petal development in sunflower. High levels of HaMADS3 that relieved the inhibition of cell proliferation, together with low levels of HaMADS7 and HaMADS8, promoted petal prolongation and maintained the morphology of ray florets. In contrast, low levels of HaMADS3 and high levels of HaMADS7 and HaMADS8 repressed petal extension and maintained the morphology of disc florets. Their coordination may contribute to the differentiation of disc and ray florets in sunflower and maintain the balance between attracting pollinators and producing offspring. Meanwhile, Pearson correlation analysis between petal length and expression levels of MADS-box genes further indicated their involvement in petal prolongation. Additionally, the analysis of cis-acting elements indicated that these three MADS-box genes may regulate petal development and floral symmetry establishment by regulating the expression activity of HaCYC2c. Our findings can provide some new understanding of the molecular regulatory network of petal development and floral morphology formation, as well as the differentiation of disc and ray florets in sunflower.
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  • 文章类型: Journal Article
    背景:全踝关节置换术(TAA)用于治疗有症状的终末期踝关节关节炎(AA)。然而,关于TAA对步态对称性的影响知之甚少。
    目的:使用归一化对称指数(NSI)和统计参数映射(SPM)确定对称性是否从手术前到TAA后两年发生变化。
    方法:从先前收集的前瞻性数据库中评估了141例晚期单侧AA患者,每个参与者在手术后两周内接受测试(Pre-Op),TAA后一年和两年。步行速度,髋部伸展角度和力矩,髋部屈曲角度,踝关节足底弯曲角度和力矩,踝关节背屈角度,重量验收(GRF1),并计算了每个肢体的推进(GRF2)垂直地面反作用力。使用NSI评估步态对称性。使用每个步态对称变量具有单个响应的线性混合效应模型来检查随访时间的固定效应(Pre-Op,一年后,2年后)和模型中步态速度作为协变量的参与者的随机效应。完成一维重复测量方差分析(ANOVA)统计参数映射(SPM)以检查时间序列NSI中的差异,以确定随访时间之间的显著差异的区域。
    结果:相对于Pre-Op值,GRF1和GRF2在会话中显示出离散指标和时间序列NSI的对称性增加。髋部伸展力矩的对称性改善最大。手术前和手术后2年的踝关节屈角度不同(p=0.010);手术前和手术后各节段的踝关节屈力矩不同(p<0.001)。与2年后相比,在Op前的早期站立阶段,时间序列踝角NSI更大。
    结论:TAA后大部分姿势阶段的对称性得到改善,表明TAA成功改善了步态对称性,未来的工作应确定这些改善是否将对称性恢复到与健康年龄匹配对照相当的水平。
    BACKGROUND: Total ankle arthroplasty (TAA) is used to treat symptomatic end-stage ankle arthritis (AA). However, little is known about TAA\'s effects on gait symmetry.
    OBJECTIVE: Determine if symmetry changes from before surgery through two years following TAA utilizing the normalized symmetry index (NSI) and statistical parametric mapping (SPM).
    METHODS: 141 patients with end-stage unilateral AA were evaluated from a previously collected prospective database, where each participant was tested within two weeks of surgery (Pre-Op), one year and two years following TAA. Walking speed, hip extension angle and moment, hip flexion angle, ankle plantarflexion angle and moment, ankle dorsiflexion angle, weight acceptance (GRF1), and propulsive (GRF2) vertical ground reaction forces were calculated for each limb. Gait symmetry was assessed using the NSI. A linear mixed effects model with a single response for each gait symmetry variable was used to examine the fixed effect of follow-up time (Pre-Op, Post-1 yr, Post-2 yr) and the random effect of participant with gait speed as a covariate in the model. A one-dimensional repeated measures analysis of variance (ANOVA) statistical parameter mapping (SPM) was completed to examine differences in the time-series NSI to determine regions of significant differences between follow-up times.
    RESULTS: Relative to Pre-Op values, GRF1, and GRF2 showed increased symmetry for discrete metrics and the time-series NSI across sessions. Hip extension moment had the largest symmetry improvement. Ankle plantarflexion angle was different between Pre-Op and Post-2 yr (p=0.010); and plantarflexion moment was different between Pre- Op and each post-operative session (p<0.001). The time-series Ankle Angle NSI was greater during the early stance phase in the Pre-Op session compared to Post-2 yr.
    CONCLUSIONS: Symmetry across most of the stance phase improved following TAA indicating that TAA successfully improves gait symmetry and future work should determine if these improvements restore symmetry to levels equivalent with health age-match controls.
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  • 文章类型: Journal Article
    单囊性成釉细胞瘤(UAM)的颌骨可以通过减压有效地减少体积,促进骨骼再生并恢复下颌对称性。这项研究定量评估了下颌骨UAM减压后下颌骨体积和对称性的变化。这项研究包括17例接受手术减压,然后进行第二阶段刮治的下颌UAM患者。收集术前、术后三维计算机断层扫描(CT)图像。测量骨体积和皮质穿孔面积以评估减压期间的骨生长。通过计算下颌骨两侧的体积比,分析下颌骨的体积对称性。在病变区域的表面上识别出十二对标志,它们的坐标用于计算下颌骨的平均不对称指数(AI)。采用配对t检验和Mann-WhitneyU检验进行统计分析。p<0.05被认为指示有统计学意义。平均减压时间为9.41±3.28个月。平均骨量增加8.07±2.41%,皮质穿孔恢复率为71.97±14.99%。下颌骨的体积对称性明显改善(p<0.05),并且观察到AI的统计学显着下降(p<0.05)。总之,UAM减压可促进下颌骨的骨骼生长和对称恢复。本评估技术在临床上可用于定量评估下颌不对称性。
    Unicystic ameloblastoma (UAM) of the jaw can be effectively reduced in volume through decompression, which promotes bone regeneration and restores jaw symmetry. This study quantitatively evaluated changes in mandible volume and symmetry following decompression of mandibular UAM. This study included 17 patients who underwent surgical decompression followed by second-stage curettage for mandibular UAM. Preoperative and postoperative three-dimensional computed tomography (CT) images were collected. Bone volume and the area of cortical perforation were measured to assess bone growth during decompression. Mandibular volumetric symmetry was analyzed by calculating the volumetric ratio of the two sides of the mandible. Twelve pairs of landmarks were identified on the surface of the lesion regions, and their coordinates were used to calculate the mean asymmetry index (AI) of the mandible. Paired t-tests and the Mann-Whitney U test were used for statistical analysis, with p < 0.05 considered indicative of statistical significance. The mean duration of decompression was 9.41 ± 3.28 months. The mean bone volume increased by 8.07 ± 2.41%, and cortical perforation recovery was 71.97 ± 14.99%. The volumetric symmetry of the mandible improved significantly (p < 0.05), and a statistically significant decrease in AI was observed (p < 0.05). In conclusion, UAM decompression enhances bone growth and symmetry recovery of the mandible. The present evaluation technique is clinically useful for quantitatively assessing mandibular asymmetry.
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  • 文章类型: Journal Article
    目的:研究客观表达上眼睑轮廓对称性的最合适的数学公式。
    方法:研究纳入31例患者的62只眼。患者的上眼睑轮廓对称性被主观归类为不良(与MR1无关),可接受,并由三名眼塑专家(高级,专家,和初级外科医生)。用ImageJ软件绘制上眼睑轮廓的贝塞尔曲线(NIH,贝塞斯达,MA,美国)。使用作者SKC在Spyder中创建的算法(Python3.7.9.),根据y轴获得左眼睑的贝塞尔曲线的对称性,两只眼睛的中瞳孔重叠。较低的曲线垂直移动到与另一条曲线相同的高度,以使MRD1相等。R2(测定系数),RMSE(均方根误差),MSE(均方误差),POC(协同效率百分比),并计算MAE(平均绝对误差)。我们使用Spearman的rho(ρ)评估了这些客观公式与三名外科医生的主观评分之间的相关性。
    结果:所有外科医生分级的RMSE和MSE的相关系数相同。高级外科医生的主观评分(N;差=8,可接受=16,好=8)与R2,RMSE,POC,MAE(分别为ρ=0.643,p<0.001,ρ=-0.607,p<0.001,ρ=0.562,p<0.001,ρ=-0.517,p<0.001)。我们发现专家外科医生的主观评分(N;差=9,可接受=13,好:10)和R2(ρ=0.611,p<0.001)之间存在很强的关系,RMSE(ρ=-0.549,p<0.001),POC(ρ=0.511,p<0.001),和MAE(ρ=-0.450,p<0.05)。我们发现初级外科医生的主观评分(N;差=6,可接受=18,好=8)和R2,RMSE,和POC(ρ:-0.517,p<0.001;ρ:-0.470,p<0.001;ρ:0.521,p<0.001;分别)和MAE之间的中等相关性(ρ:-0.394,p<0.05)。用R2观察到最高的相关性。
    结论:RMSE,MSE,POC,MAE,尤其是R2,可以定量表达上眼睑轮廓对称性,与眼整形外科医生相当。在高级外科医生和R2之间观察到最高的相关性,并且随着外科医生的经验而降低。
    OBJECTIVE: Investigate the most appropriate mathematical formula to objectively express upper eyelid contour symmetry.
    METHODS: 62 eyes of 31 patients were included in the study. The upper eyelid contour symmetry of the patients was classified subjectively (independent of MRD1) as poor, acceptable, and good by three oculoplastic specialists (senior, expert, and junior surgeon). Bézier curves of the upper lid contour were drawn with ImageJ software (NIH, Bethesda, MA, USA). Using the algorithms created by Author SKC in Spyder (Python 3.7.9.), the symmetry of the Bézier curves of the left eyelids were obtained according to the y-axis, and the mid-pupils of both eyes were superimposed. The lower curve moved vertically to the equal height of the other curve to equalize MRD1\'s. R2 (Coefficient of determination), RMSE (Root-mean-square error), MSE (Mean squared error), POC (Percentage of co-efficiency), and MAE (Mean absolute error) were calculated. We evaluated the correlation between these objective formulas and the subjective grading of three surgeons using Spearman\'s rho (ρ).
    RESULTS: The correlation coefficient of RMSE and MSE were the same for all surgeons grading. There was a strong correlation between the senior surgeon\'s subjective scoring (N; poor = 8, acceptable = 16, good = 8) and R2, RMSE, POC, MAE (ρ = 0.643, p < 0.001, ρ = -0.607, p < 0.001, ρ = 0.562, p < 0.001, ρ = -0.517, p < 0.001, respectively). We found a strong relationship between the expert surgeon\'s subjective scoring (N; poor = 9, acceptable = 13, good:10) and R2 (ρ = 0.611, p < 0.001), RMSE (ρ = -0.549, p < 0.001), POC (ρ = 0.511, p < 0.001), and MAE (ρ = -0.450, p < 0.05). We found a strong correlation between junior surgeon\'s subjective scoring (N; poor = 6, acceptable = 18, good = 8) and R2, RMSE, and POC (ρ: -0.517, p < 0.001; ρ: -0.470, p < 0.001; ρ: 0.521, p < 0.001; respectively) and moderate correlation between MAE (ρ:-0.394, p < 0.05). The highest correlation is observed with R2.
    CONCLUSIONS: RMSE, MSE, POC, MAE, and especially R2, may quantitatively express upper eyelid contour symmetry, comparable with the oculoplastic surgeon. The highest correlation was observed between the senior surgeon and R2, and decreases with the experience of the surgeon.
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  • 文章类型: Journal Article
    这是《量子物理学中的孤子》特刊的社论。
    This is an Editorial for the Special Issue on Solitons in Quantum Physics.
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  • 文章类型: Journal Article
    本研究旨在研究中国骨盆的对称性。
    将50个中国骨盆的计算机断层扫描图像转换为3D模型,并将骨盆的左侧反映在Mimics软件上。然后,使用Geomagic软件的最近点算法功能将反射的左侧模型与右侧对齐以进行对称性分析。还计算了骨盆两侧的体积和表面积。平均值标准偏差(SD),±2mm范围内允许偏差的平均百分比,测量体积和表面积的百分比差异以比较骨盆对称性.此外,比较了与年龄和性别相关的骨盆双侧对称性的分布。
    平均SD为1.15±0.16mm,允许偏差的平均百分比为90.82%±4.67%。偏差颜色图显示,特定的不对称区域主要位于主要的肌肉或韧带附着部位以及the关节表面。骨盆两侧的体积或表面积均无显着差异。此外,与性别和年龄分布有关的任何指标均无差异。
    我们的结果表明骨盆具有高度的双侧对称性,这证实了使用对侧骨盆模型来创建适用于骨折和骨破坏治疗的完全患者特定和定制的骨盆植入物的潜力。
    UNASSIGNED: This study aimed to investigate the symmetry of the Chinese pelvis.
    UNASSIGNED: Computed tomography scan images of each of 50 Chinese pelvises were converted to 3D models and the left sides of the pelvises were reflected on Mimics software. Then, the reflected left side model was aligned with the right side using the closest point algorithm function of Geomagic software to perform symmetry analysis. The volume and surface area of either side of the pelvises were also calculated. The mean standard deviation (SD), the mean percentage of permissible deviations within the ±2 mm range, the percentage differences in volume and surface area were measured to compare pelvic symmetry. In addition, the distribution of pelvic bilateral symmetry associated with both age and sex were compared.
    UNASSIGNED: The mean SD was 1.15 ± 0.16 mm and the mean percentage of permissible deviations was 90.82% ± 4.67%. The deviation color maps showed that the specific areas of asymmetry were primarily localized to major muscle or ligament attachment sites and the sacroiliac joint surfaces. There was no significant difference between the bilateral sides of the pelvis in either volume or surface area. Additionally, no difference in any indexes was exhibited in relation to sex and age distribution.
    UNASSIGNED: Our results demonstrated that the pelvis has high bilateral symmetry, which confirmed the potential of using contralateral pelvic models to create fully patient-specific and custom-made pelvic implants applicable for the treatment of fracture and bony destruction.
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  • 文章类型: Journal Article
    简并性和对称性在量子系统中有着深远的关系。这里,我们报道了具有几乎对称横截面形状的PbTe纳米线中的门可调谐子带简并性。由于没有量子化平台,在电子传输中揭示了简并性。利用双门设计,我们可以施加电场来提升简并性,反映为高原的出现。在先前的纳米线实验中观察到这种简并性及其可调提升是具有挑战性的,可能是由于混乱。数值模拟可以定性地捕获我们的观察结果,为未来的应用提供器件参数的光照。
    Degeneracy and symmetry have a profound relation in quantum systems. Here, we report gate-tunable subband degeneracy in PbTe nanowires with a nearly symmetric cross-sectional shape. The degeneracy is revealed in electron transport by the absence of a quantized plateau. Utilizing a dual gate design, we can apply an electric field to lift the degeneracy, reflected as emergence of the plateau. This degeneracy and its tunable lifting were challenging to observe in previous nanowire experiments, possibly due to disorder. Numerical simulations can qualitatively capture our observation, shedding light on device parameters for future applications.
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  • 文章类型: Journal Article
    游泳中的不对称可能是由于技术差或四肢之间的协调,降低产生推进力和增加阻力的能力。因此,这项研究旨在比较大小和确定的一致性的等速峰值扭矩不对称性的角速度之间的肩关节运动的内外旋转,屈曲,和延伸。21名竞技游泳运动员在内外旋转运动中以60°/s(3次重复)和180°/s(20次重复)进行同心动作,屈曲,使用等速测力计延伸肩部,峰值扭矩和不对称指数是整个测试的常见指标。结果表明,内部旋转的不对称性更大(16.86vs.9.86;p=0.007)和屈曲(12.06vs.7.35;p=0.008)在60与180°/s,分别。角速度之间不对称方向的一致性水平相当大(Kappa:0.40至0.69)。评估不同运动和角速度下的等速扭矩会导致不同程度的不对称性。肌肉力量不对称会影响游泳过程中的推进效率和运动协调。了解肌肉不对称可以制定有针对性和个性化的训练计划,以纠正力量失衡。
    Asymmetries in swimming can be the result of poor technique or coordination between limbs, reducing the ability to produce propulsive force and increasing resistive drag. Therefore, this study aimed to compare the magnitude and determine the consistency of isokinetic peak torque asymmetries between the angular velocities of in the shoulder joint movements of internal and external rotation, flexion, and extension. Twenty-one competitive swimmers performed concentric actions at 60°/s (3 repetitions) and 180°/s (20 repetitions) in the movements of internal and external rotation, flexion, and extension of the shoulders using an isokinetic dynamometer, with the peak torque and asymmetry index being common metrics across the tests. The results showed a greater magnitude of asymmetry in internal rotation (16.86 vs. 9.86; p = 0.007) and flexion (12.06 vs. 7.35; p = 0.008) at 60 vs. 180°/s, respectively. The agreement levels of the direction of asymmetries between angular velocities were fair to substantial (Kappa: 0.40 to 0.69). Evaluating isokinetic torque in different movements and angular velocities resulted in different levels of asymmetry. Muscle force asymmetries can impact propulsion efficiency and movement coordination during swimming. Understanding muscle asymmetries allows the development of targeted and individualised training programmes to correct strength imbalances.
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  • 文章类型: Journal Article
    花是被子植物门的特征性植物结构,该植物结构由被认为是从同源结构到叶子的器官组成,以专门实现独特的功能:繁殖。对称形状,颜色,和气味都在花卉生物学中起着重要的功能作用。花对称性的演变和单个花部分的形态(萼片,花瓣,雄蕊,和心皮)极大地促进了开花植物物种生殖策略的多样性。这种多样性促进了授粉的吸引力,保护配子,高效施肥,和种子生产。对称性,身体轴的建立,和命运的决定紧密相连。建立器官的复杂遗传网络,组织,和细胞身份,以及跨越身体轴的生长调节剂,正在该领域稳步阐明。在这次审查中,我们总结了丰富的研究已经在我们的指尖开始编织在一起,涉及指定器官身份在花可能相互作用的独立过程,提供有关如何协调身份确定和轴向调节以告知对称的花器官结构的功能观点。
    Flowers are plant structures characteristic of the phylum Angiosperms composed of organs thought to have emerged from homologous structures to leaves in order to specialize in a distinctive function: reproduction. Symmetric shapes, colours, and scents all play important functional roles in flower biology. The evolution of flower symmetry and the morphology of individual flower parts (sepals, petals, stamens, and carpels) has significantly contributed to the diversity of reproductive strategies across flowering plant species. This diversity facilitates attractiveness for pollination, protection of gametes, efficient fertilization, and seed production. Symmetry, the establishment of body axes, and fate determination are tightly linked. The complex genetic networks underlying the establishment of organ, tissue, and cellular identity, as well as the growth regulators acting across the body axes, are steadily being elucidated in the field. In this review, we summarise the wealth of research already at our fingertips to begin weaving together how separate processes involved in specifying organ identity within the flower may interact, providing a functional perspective on how identity determination and axial regulation may be coordinated to inform symmetrical floral organ structures.
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  • 文章类型: Journal Article
    布里奇曼曾经在热力学上反思过,热力学定律是由热力学的伟大创始人以现在的形式制定的,Kelvin和Clausius,在所有基本的物理事实出现之前,此后,没有对基本面进行充分的重新审查。热力学仍然有未知的可能性等待探索。本文首先简要回顾了克劳修斯关于热力学第二定律的工作,并重新评估了克劳修斯陈述的内容。这篇评论告诉克劳修斯最初所说的热力学第二定律是,事实上,可逆循环中的变换等价定理(TET)。在此基础上,提出了克劳修斯TET的一种新的对称形式。这个定理说两个变换,即,热量转化为功,功从高压转化为低压,在可逆的功-热循环中应该是等效的。在具有两个工作储层(两个压力)的循环的基础上开发了新的热力学循环定律,这丰富了热力学第二定律的基础。
    Bridgman once reflected on thermodynamics that the laws of thermodynamics were formulated in their present form by the great founders of thermodynamics, Kelvin and Clausius, before all the essential physical facts were in, and there has been no adequate reexamination of the fundamentals since. Thermodynamics still has unknown possibilities waiting to be explored. This paper begins with a brief review of Clausius\'s work on the second law of thermodynamics and a reassessment of the content of Clausius\'s statement. The review tells that what Clausius originally referred to as the second law of thermodynamics was, in fact, the theorem of equivalence of transformations (TET) in a reversible cycle. On this basis, a new symmetric form of Clausius\'s TET is proposed. This theorem says that the two transformations, i.e., the transformation of heat to work and the transformation of work from high pressure to low pressure, should be equivalent in a reversible work-to-heat cycle. New thermodynamic cyclic laws are developed on the basis of the cycle with two work reservoirs (two pressures), which enriches the fundamental of the second law of thermodynamics.
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