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1.
Dev Dyn ; 2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-38984461

RESUMO

BACKGROUND: Mouse nodal immotile cilia mechanically sense the bending direction for left-right (L-R) determination and activate the left-side-specific signaling cascade, leading to increased Nodal activity. Asymmetric distribution of Pkd2, a crucial channel for L-R determination, on immotile cilia has been reported recently. However, the causal relationship between the asymmetric Pkd2 distribution and direction-dependent flow sensing is not well understood. Furthermore, the underlying molecular mechanism directing this asymmetric Pkd2 distribution remains unclear. RESULTS: The effects of several recombinant proteins and inhibitors on the Pkd2 distribution were analyzed using super-resolution microscopy. Notably, bone morphogenetic protein 4 (BMP4) affected the Pkd2 distribution. Additionally, three-dimensional manipulation of nodal immotile cilia using optical tweezers revealed that excess BMP4 caused defects in the mechanosensing ability of the cilia. CONCLUSIONS: Experimental data together with model calculations suggest that BMP4 regulates the asymmetric distribution of Pkd2 in nodal immotile cilia, thereby affecting the ability of these cilia to sense the bending direction for L-R determination. This study, for the first time, provides insight into the relationship between the asymmetric protein distribution in cilia and their function.

2.
Sci Rep ; 14(1): 15492, 2024 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-38969711

RESUMO

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.


Assuntos
Ameloblastoma , Descompressão Cirúrgica , Imageamento Tridimensional , Mandíbula , Tomografia Computadorizada por Raios X , Humanos , Ameloblastoma/cirurgia , Ameloblastoma/diagnóstico por imagem , Feminino , Masculino , Mandíbula/cirurgia , Mandíbula/diagnóstico por imagem , Adulto , Descompressão Cirúrgica/métodos , Imageamento Tridimensional/métodos , Tomografia Computadorizada por Raios X/métodos , Adulto Jovem , Adolescente , Pessoa de Meia-Idade , Neoplasias Mandibulares/cirurgia , Neoplasias Mandibulares/diagnóstico por imagem , Desenvolvimento Ósseo , Regeneração Óssea
3.
Sci Rep ; 14(1): 15510, 2024 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-38969827

RESUMO

The optoelectronic and structural characteristics of the Zn1-xCrxSe (0 ≤ x ≤ 1) semiconductor are reported by employing density functional theory (DFT) within the mBJ potential. The findings revealed that the lattice constant decreases with increasing Cr concentration, although the bulk modulus exhibits the opposite trend. ZnSe is a direct bandgap material; however, a change from direct to indirect electronic bandgap has been seen with Cr presence. This transition is caused by structural alterations by Cr and defects forming, which results in novel optical features, including electronic transitions. The electronic bandgap decreases from 2.769 to 0.216 eV, allowing phonons to participate and improving optical absorption. A higher concentration of Cr boosts infrared absorption and these Cr-based ZnSe (ZnCrSe) semiconductors also cover a wider spectrum in the visible range from red to blue light. Important optical parameters such as reflectance, optical conductivity, optical bandgap, extinction coefficient, refractive index, magnetization factor, and energy loss function are discussed, providing a theoretical understanding of the diverse applications of ZnCrSe semiconductors in photonic and optoelectronic devices.

4.
Acta Crystallogr E Crystallogr Commun ; 80(Pt 7): 713-716, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38974161

RESUMO

The synthesis, crystal structure, and a Hirshfeld surface analysis of tris-{N,N-diethyl-N'-[(4-nitro-phen-yl)(oxo)meth-yl]carbamimido-thio-ato}cobalt(III) conducted at 180 K are presented. The complex consists of three N,N-diethyl-N'-[(4-nitro-benzene)(oxo)meth-yl]carbamimido-thio-ato ligands, threefold sym-metric-ally bonded about the CoIII ion, in approximately octa-hedral coordination, which generates a triple of individually near planar metallacyclic (Co-S-C-N-C-O) rings. The overall geometry of the complex is determined by the mutual orientation of each metallacycle about the crystallographically imposed threefold axis [dihedral angles = 81.70 (2)°] and by the dihedral angles between the various planar groups within each asymmetric unit [metallacycle to benzene ring = 13.83 (7)°; benzene ring to nitro group = 17.494 (8)°]. The complexes stack in anti-parallel columns about the axis of the space group (P), generating solvent-accessible channels along [001]. These channels contain ill-defined, multiply disordered, partial-occupancy solvent. Atom-atom contacts in the crystal packing predominantly (∼96%) involve hydrogen, the most abundant types being H⋯H (36.6%), H⋯O (31.0%), H⋯C (19.2%), H⋯N (4.8%), and H⋯S (4.4%).

5.
PeerJ ; 12: e17586, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38974413

RESUMO

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.


Assuntos
Flores , Regulação da Expressão Gênica de Plantas , Helianthus , Proteínas de Domínio MADS , Proteínas de Plantas , Helianthus/genética , Helianthus/crescimento & desenvolvimento , Helianthus/metabolismo , Flores/genética , Flores/crescimento & desenvolvimento , Proteínas de Domínio MADS/genética , Proteínas de Domínio MADS/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
6.
Heliyon ; 10(12): e32207, 2024 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-38975224

RESUMO

This study presents an analysis and evaluation of gait asymmetry (GA) based on the temporal gait parameters identified using a portable gait event detection system, placed on the lateral side of the shank of both lower extremities of the participants. Assessment of GA was carried out with seven control subjects (CS), one transfemoral amputee (TFA) and one transtibial amputee (TTA) while walking at different speeds on overground (OG) and treadmill (TM). Gait cycle duration (GCD), stance phase duration (SPD), swing phase duration (SwPD), and the sub-phases of the gait cycle (GC) such as Loading-Response (LR), Foot-Flat (FF), and Push-Off (PO), Swing-1 (SW-1) and Swing-2 (SW-2) were evaluated. The results revealed that GCD showed less asymmetry as compared to other temporal parameters in both groups. A significant difference (p < 0.05) was observed between the groups for SPD and SwPD with lower limb amputees (LLA) having a longer stance and shorter swing phase for their intact side compared to their amputated side, resulting, large GA for TFA compared to CS and TTA. The findings could potentially contribute towards a better understanding of gait characteristics in LLA and provide a guide in the design and control of lower limb prosthetics/orthotics.

7.
Int Ophthalmol ; 44(1): 303, 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38954051

RESUMO

PURPOSE: 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.


Assuntos
Pálpebras , Humanos , Pálpebras/patologia , Feminino , Masculino , Pessoa de Meia-Idade , Algoritmos , Idoso , Adulto , Blefaroplastia/métodos
8.
J Orthop Res ; 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38956422

RESUMO

Total knee arthroplasty (TKA) and unicompartmental knee arthroplasty (UKA) are effective surgeries to treat end-stage knee osteoarthritis. Clinicians assume that TKA alters knee kinematics while UKA preserves native knee kinematics; however, few studies of in vivo kinematics have evaluated this assumption. This study used biplane radiography to compare side-to-side tibiofemoral kinematics during chair rise, stair ascent, and walking in 16 patients who received either TKA or UKA. We hypothesized that TKA knees would have significant kinematic changes and increased asymmetry with the contralateral knee, while UKA knee kinematics would not change after surgery and preoperative knee symmetry would be maintained. Native bone and implant motion were tracked using a volumetric model-based tracking technique. Six degrees of freedom kinematics were calculated throughout each motion. Kinematics were compared between the operated and contralateral knees pre- and post-surgery using a linear mixed-effects model. TKA knees became less varus with the tibia more medial, posterior, and distal relative to the femur. UKA knees became less varus with the tibia less lateral on average. Postoperative TKA knees were in less varus than UKA knees on average and at low flexion angles, with an internally rotated tibia during chair rise and stair ascent. At high flexion angles, the tibia was more medial and posterior after TKA than UKA. Side-to-side kinematic symmetry worsened after TKA but was maintained or improved after UKA. Greater understanding of kinematic differences between operated and contralateral knees after surgery may help surgeons understand why some patients remain unsatisfied with their new knees.

9.
Rep Prog Phys ; 87(7)2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38957897

RESUMO

Non-Hermitian matrices are ubiquitous in the description of nature ranging from classical dissipative systems, including optical, electrical, and mechanical metamaterials, to scattering of waves and open quantum many-body systems. Seminal line-gap and point-gap classifications of non-Hermitian systems using K-theory have deepened the understanding of many physical phenomena. However, ample systems remain beyond this description; reference points and lines do not in general distinguish whether multiple non-Hermitian bands exhibit intriguing exceptional points, spectral braids and crossings. To address this we consider two different notions: non-Hermitian band gaps and separation gaps that crucially encompass a broad class of multi-band scenarios, enabling the description of generic band structures with symmetries. With these concepts, we provide a unified and comprehensive classification of both gapped and nodal systems in the presence of physically relevant parity-time (PT) and pseudo-Hermitian symmetries using homotopy theory. This uncovers new stable topology stemming from both eigenvalues and wave functions, and remarkably also implies distinct fragile topological phases. In particular, we reveal different Abelian and non-Abelian phases inPT-symmetric systems, described by frame and braid topology. The corresponding invariants are robust to symmetry-preserving perturbations that do not induce (exceptional) degeneracy, and they also predict the deformation rules of nodal phases. We further demonstrate that spontaneousPTsymmetry breaking is captured by Chern-Euler and Chern-Stiefel-Whitney descriptions, a fingerprint of unprecedented non-Hermitian topology previously overlooked. These results open the door for theoretical and experimental exploration of a rich variety of novel topological phenomena in a wide range of physical platforms.

10.
Angew Chem Int Ed Engl ; : e202410219, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38949846

RESUMO

Pd(II)-based low-symmetry coordination cages possessing anisotropic cavities are of great interest. The common strategies employed to achieve such cages utilize either more than one type of symmetrical ligands (e.g., Laa, Lbb, etc.) or only one type of unsymmetrical ligand (e.g., Lab). To significantly enhance the anisotropy, we have designed two unsymmetrical bidentate ligands i.e., Lab and Lcd, aiming a low-symmetry Pd2Lab2Lcd2-type cage. It was accomplished by high-fidelity integrative self-sorting of two different low-symmetry cages having Pd2Lab4 and Pd4Lcd8-type architectures (homoleptic complexes of the designed ligands). Structural constraints and geometry complementarity in the ligand design drive the non-statistical exclusive self-assembly of the Pd2Lab2Lcd2-type cage. By taking advantage of the complemental geometries between ligands, a low-symmetry Pd2Lab2Lcc2-type cage was also obtained. Heteromeric completive self-sorting of three homoleptic assemblies (Pd2Lab4, Pd4Lcc8 and Pd4Lcd8-type cages) into an exclusive mixture of Pd2Lab2Lcd2 and Pd2Lab2Lcc2-type mixed ligated assemblies was demonstrated through cage-to-cage transformations.

11.
Gait Posture ; 113: 272-279, 2024 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-38970929

RESUMO

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. RESEARCH QUESTION: 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. SIGNIFICANCE: 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.

12.
Artigo em Inglês | MEDLINE | ID: mdl-38870995

RESUMO

In this short article, we overview a concept of electronic toroidal multipoles, and their ordering with associated physical properties in non-magnetic and magnetic materials. The toroidal multipoles are introduced as microscopic electronic variables in view of symmetry and connection to Dirac theory. They are classified according to crystallographic and magnetic point groups, which allows us to discuss various possible cross correlations in a transparent and unified manner. The representative examples of toroidal orders and related phenomena, and the mutual relationship between these orders are given, with focusing on monopoles and dipoles. The concept of toroidal multipoles would promote future studies toward observations and identifications of unknown electronic phases and their related physical phenomena. .

13.
Cureus ; 16(5): e60516, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38883057

RESUMO

Background Many sporting activities demand multidirectional skills and movements, emphasizing the importance of various fitness components such as functional stability, strength, power, endurance, and range of motion. These aspects must be thoroughly assessed before athletes can return to sports safely following an injury. Although the single-leg hop test (SHT) is widely used as the gold standard for evaluating joint stability, it has limitations in assessing multidirectional movements. Therefore, further research is necessary to explore whether increasing the dynamicity of the hop test in different directions enhances its sensitivity in assessing knee joint stability across all four directions. The objective of this study was to investigate the applicability of a new functional assessment tool, the quadrant hop test (QHT), for evaluating lower limb functional stability. Methodology One hundred nineteen amateur sportsmen who are in the age group of 18-25 years with a limb symmetry index of the lower limb calculated through SHT of >80% were included. All the participants performed the SHT, a triple hop test (THT), a crossover hop test (CHT), and the QHT on two different days, with two investigators assessing the QHT on different days and then recording the measurements of Hop distance. Results The mean difference between SHT, THT, and CHT with QHT was 4.59%, with a moderate correlation between all the hop tests. The Cronbach's alpha revealed good intra-rater (0.917) and inter-rater reliability (0.912) of the QHT. Conclusion The QHT proves to be a reliable and valid measure for assessing the functional stability of the lower limb and is 4.59% more sensitive than SHT, THT, and CHT in assessing knee stability and in return to sports criteria.

14.
Natl Sci Rev ; 11(7): nwae175, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38883296

RESUMO

Anisotropy is a significant and prevalent characteristic of materials, conferring orientation-dependent properties, meaning that the creation of original symmetry enables key functionality that is not found in nature. Even with the advancements in atomic machining, synthesis of separated symmetry in different directions within a single structure remains an extraordinary challenge. Here, we successfully fabricate NiS ultrafine nanorods with separated symmetry along two directions. The atomic structure of the nanorod exhibits rotational symmetry in the radial direction, while its axial direction is characterized by divergent translational symmetry, surpassing the conventional crystalline structures known to date. It does not fit the traditional description of the space group and the point group in three dimensions, so we define it as a new structure in which translational symmetry and rotational symmetry are separated. Further corroborating the atomic symmetric separation in the electronic structure, we observed the combination of stripe and vortex magnetic domains in a single nanorod with different directions, in accordance with the atomic structure. The manipulation of nanostructure at the atomic level introduces a novel approach to regulate new properties finely, leading to the proposal of new nanotechnology mechanisms.

15.
Knee Surg Relat Res ; 36(1): 22, 2024 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-38886848

RESUMO

BACKGROUND: Biomechanical changes and neuromuscular adaptations have been suggested as risk factors of secondary injury in individuals after anterior cruciate ligament reconstruction (ACLr). To achieve a better understanding of preventive mechanisms, movement quality is an important factor of consideration. Few studies have explored time-series analysis during landing alongside clinical performance in injured and non-injured individuals. The purpose of the study was to investigate the biomechanical risks of recurrent injury by comparing clinical and jump-landing performance assessments between athletes with ACLr and healthy controls. METHOD: This study was observational study. Sixteen athletes with and without ACLr voluntarily participated in clinical and laboratory measurements. Single-leg hop distance, isokinetic tests, landing error score, and limb symmetry index (LSI) were included in clinical report. Lower limb movements were recorded to measure joint biomechanics during multi-directional landings in motion analysis laboratory. Hip-knee angle and angular velocity were explored using discrete time-point analysis, and a two-way mixed analysis of variance (2 × 4, group × jump-landing direction) was used for statistical analysis. Time series and hip-knee coordination analyses were performed using statistical parametric mapping and descriptive techniques. RESULTS: Significantly lower single-leg hop distance was noted in ACLr group (158.10 cm) compared to control group (178.38 cm). Although the hip and knee moments showed significant differences between four directions (p < 0.01), no group effect was observed (p > 0.05). Statistical parametric mapping showed significant differences (p ≤ 0.05) between groups for hip abduction and coordinate plot of hip and knee joints. Athletes with ACLr demonstrated a higher velocity of hip adduction. Time-series analysis revealed differences in coordination between groups for frontal hip and knee motion. CONCLUSIONS: Athletes with ACLr landed with poor hip adduction control and stiffer knee on the involved side. Multi-directions landing should be considered over the entire time series, which may facilitate improved movement quality and return to sports in athletes with ACLr.

16.
Materials (Basel) ; 17(11)2024 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-38893882

RESUMO

Rules that control the arrangement of chemical species within crystalline arrays of different symmetry and structural complexity are of fundamental importance in geoscience, material science, physics, and chemistry. Here, the volume of crystal phases is normalized by their ionic volume and an algebraic index that is based on their space-group and crystal site symmetries. In correlation with the number of chemical formula units Z, the normalized volumes exhibit upper and lower limits of possible structures. A bottleneck of narrowing limits occurs for Z around 80 to 100, but the field of allowed crystalline configurations widens above 100 due to a change in the slope of the lower limit. For small Z, the highest count of structures is closer to the upper limit, but at large Z, most materials assume structures close to the lower limit. In particular, for large Z, the normalized volume provides rather narrow constraints for the prediction of novel crystalline phases. In addition, an index of higher and lower complexity of crystalline phases is derived from the normalized volume and tested against key criteria.

17.
ACS Appl Mater Interfaces ; 16(24): 31247-31253, 2024 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-38844450

RESUMO

As Coulomb drag near charge neutrality (CN) is driven by fluctuations or inhomogeneity in charge density, the topology should play an extremely important role. Interlinking Coulomb drag and topology could reveal how the system's nontrivial topology influences the electron-electron interactions at the quantum level. However, such an aspect is overlooked as most studies focus on symmetric drag systems without topology. To understand this topological aspect, we need to study Coulomb drag in an asymmetric system with a broken inversion symmetry and strong spin-orbit coupling (SOC). Here we experimentally demonstrate the energy-driven Coulomb drag in an asymmetric van der Waals heterostructure composed of black phosphorus and rhenium disulfide characterized by broken inversion symmetry. Temperature-dependent transport measurements near CN provide compelling evidence for the energy-driven Coulomb drag due to electron-hole coupling that is energetically favored in a broken-gap heterojunction, as confirmed by Hall coefficient sign reversal with temperature. Moreover, contrary to the symmetric devices, our results exhibit magnetic-field-free, i.e., topology-driven, Hall drag, revealing an intrinsic coupling between energy and charge modes. This is the manifestation of nonzero Berry curvature, akin to a magnetic field in momentum space, in a Rashba system, which arises from the SOC and broken inversion symmetry of the heterostructure.

18.
Plant Cell Physiol ; 2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-38903045

RESUMO

The standout characteristic of the orchid perianth is the transformation of the upper median petal into a distinctively formed lip, which gives orchid flowers their typically zygomorphic symmetry and makes them the most popular ornamental plants worldwide. To study orchid flower development, two WUSCHEL-related homeobox (WOX) genes, PaWOX3 and PaWOX3B, were identified in Phalaenopsis. PaWOX3 and PaWOX3B mRNAs accumulate abundantly during early reproductive development and perianths of young buds, significantly decrease in mature flower and absent in vegetative leaves and roots. PaWOX3 and PaWOX3B virus-induced gene silencing (VIGS) knockdown in Phalaenopsis significantly reduces floral bud numbers, suggesting that PaWOX3/PaWOX3B may be involved in flower initiation. Transgenic Arabidopsis ectopically expressing repressor forms of PaWOX3/PaWOX3B and their Oncidium orthologue, OnPRS, exhibit lateral organ development defects, implicating these genes likely have function in regulating growth and differentiation for lateral organs. Neither PaWOX3, PaWOX3B single nor PaWOX3/PaWOX3B double VIGS Phalaenopsis altered the flower morphology. Interestingly, double silencing of PaWOX3 or PaWOX3B with OAGL6-2, which controlled the identity/formation of lips, altered the symmetry of 'BigLip' produced in OAGL6-2 VIGS. This result indicated that the levels of PaWOX3/PaWOX3B are still sufficient to maintain the symmetry for the OAGL6-2 VIGS 'BigLip'. However, the symmetry of the OAGL6-2 VIGS 'BigLip' can not be maintained once the expression of PaWOX3 or PaWOX3B is further reduced. Thus, in addition to control lip identity, this study further found that OAGL6-2 could cooperate with functionally redundant PaWOX3/PaWOX3B in maintaining the symmetric axis of lip.

19.
Des Monomers Polym ; 27(1): 35-50, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38903406

RESUMO

The C3-symmetry ionic polymer PPyTri has been designed with multi-walled carbon nanotubes (MWCNTs) or graphene nanoplatelets (GNPs) and studied as an ultrasensitive electrochemical sensor for trace Hg(II) detection. The synthesis approach incorporated attaching three pyridinium cationic components with chloride anions to the triazine core. The precursors, BPy, were synthesized using a condensation process involving 4-pyridine carboxaldehyde and focused nicotinic hydrazide. The polymer PPyTri was further modified with either MWCNTs or GNPs. The resulting ionic polymer PPyTri and its fabricated nanocomposites were characterized using infrared (IR), nuclear magnetic resonance (NMR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and powder X-ray diffraction (XRD). The analysis revealed that both the polymer and its nanocomposites have semi-crystalline structures. The electroactivity of the designed nanocomposites toward Hg + 2 ions revealed that among the nanocomposites and bare copolymer, the glassy carbon electrode (GCE) adapted with the PPyTri GNPs-5% exhibited the greatest current response over a wide range of Hg + 2 concentrations. The nanocomposite-modified electrode presented an excellent sensitivity of 83.33 µAµM - 1 cm - 2, a low detection limit of 0.033 nM, and a linear dynamic range of 0.1 nM to 0.01 mM (R2 = 0.9945).

20.
J Phys Condens Matter ; 36(37)2024 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-38899401

RESUMO

Parity-time-reversal symmetry (PTsymmetry), a symmetry for the combined operations of space inversion (P) and time reversal (T), is a fundamental concept of physics and characterizes the functionality of materials as well asPandTsymmetries. In particular, thePT-symmetric systems can be found in the centrosymmetric crystals undergoing the parity-violating magnetic order which we call the odd-parity magnetic multipole order. While this spontaneous order leavesPTsymmetry intact, the simultaneous violation ofPandTsymmetries gives rise to various emergent responses that are qualitatively different from those allowed by the nonmagneticP-symmetry breaking or by the ferromagnetic order. In this review, we introduce candidates hosting the intriguing spontaneous order and overview the characteristic physical responses. Various off-diagonal and/or nonreciprocal responses are identified, which are closely related to the unusual electronic structures such as hidden spin-momentum locking and asymmetric band dispersion.

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