We report on optical measurements of the 1D Heisenberg antiferromagnet KCuF3. The crystal-field excitations of the Cu2+ ions have been observed and their temperature dependence can be understood in terms of magnetic and exchange-induced dipole mechanisms and vibronic interactions. Above TN we observe a new temperature scale TS characterized by the emergence of narrow absorption features that correlate with changes of the orbital ordering as observed by Paolasini et al. [Phys. Rev. Lett. 88, 106403 (2002)]. The appearance of these optical transitions provides evidence for a symmetry change above the Néel temperature that affects the orbital ordering and paves the way for the antiferromagnetic ordering.
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http://dx.doi.org/10.1103/PhysRevLett.101.157406 | DOI Listing |
Cureus
December 2024
Department of Orthodontics and Dentofacial Orthopedics, Government Dental College, Thiruvananthapuram, Thiruvananthapuram, IND.
Introduction Unilateral cleft lip and palate (UCLP) often leads to maxillary hypoplasia and skeletal Class III malocclusion, with conflicting evidence on mandibular asymmetry. This study evaluated vertical mandibular asymmetry in UCLP patients, comparing them with non-cleft individuals having skeletal Class III and Class I malocclusions. Methods Mandibular asymmetry was evaluated using orthopantomograms (OPGs) from 90 subjects divided into three groups of 30 each: UCLP group, non-cleft skeletal Class III, and non-cleft skeletal Class I.
View Article and Find Full Text PDFOrthop J Sports Med
January 2025
Faculty of Health Sciences, Hokkaido University, Sapporo, Japan.
Background: Understanding the factors associated with poor recovery over time after anterior cruciate ligament reconstruction (ACLR) helps clinicians identify patients who are at risk and targets for an intervention.
Purpose: To determine the factors associated with improvement in subjective knee function from 6 to 12 months after ACLR.
Study Design: Case-control study; Level of evidence, 3.
Orthop J Sports Med
January 2025
Department of Kinesiology, University of Virginia, Charlottesville, Virginia, USA.
Background: There has been increased interest in lateral extra-articular procedures, such as anterolateral ligament reconstruction (ALLR) or lateral extra-articular tenodesis (LET), to reduce anterolateral rotation instability of the knee after anterior cruciate ligament reconstruction (ACLR). Despite promising surgical outcomes with these techniques, their impact on knee strength recovery is unknown.
Hypothesis: Patients undergoing lateral extra-articular procedures at the time of ACLR would have impaired thigh muscle strength at 6 to 9 months after surgery.
Medicina (Kaunas)
January 2025
Hospital Virgen de la Concha, 49022 Zamora, Spain.
: Up to 27% of anterior cruciate ligament (ACL) reconstruction cases result in a residual positive pivot shift sign, indicating anteroposterior and rotational instability. This instability can compromise returning to sports and increase the risk of further injuries. The biomechanical role of the anterolateral ligament (ALL) in controlling internal knee rotation is well known.
View Article and Find Full Text PDFUsing the first principle calculations, we propose a boron and nitrogen cluster incorporated graphene system for efficient valley polarization. The broken spatial inversion symmetry results in high Berry curvature at and valleys of the hexagonal Brillouin zone in this semiconducting system. The consideration of excitonic quasiparticles within the approximation along with their scattering processes using the many-body Bethe-Salpeter equation gives rise to an optical gap of 1.
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