Orbital Structure Research Articles

Tuning d-Orbital Electronic Structure via Au-Intercalated Two-Dimensional Fe3GeTe2 to Increase Surface Plasmon Activity.

While extensive research has been dedicated to plasmon tuning within non-noble metals, prior investigations primarily concentrated on markedly augmenting the inherently low concentration of free carriers in materials with minimal consideration given to the influence of electron orbitals on surface plasmons. Here, we achieve successful intercalation of Au atoms into the layered structure of Fe3GeTe2 (FGT), thereby exerting control over the orbital electronic states or structure of FGT. This intervention not only amplifies the charge density and electron mobility but also mitigates the loss associated with interband transitions, resulting in increased two-dimensional FGT surface plasmon activity. As a consequence, Au-intercalated FGT detects crystal violet molecules as a surface-enhanced Raman scattering substrate, and the detection lines are 3 orders of magnitude higher than before Au intercalation. Our work provides insight for further studies on plasmon effects and the relation between surface plasmon resonance behavior and electronic structures.

Orbital Torus Imaging: Acceleration, Density, and Dark Matter in the Galactic Disk Measured with Element Abundance Gradients

Under the assumption of a simple and time-invariant gravitational potential, many Galactic dynamics techniques infer the milky Way’s mass and dark matter distributions from stellar kinematic observations. These methods typically rely on parameterized potential models of the Galaxy and must take into account nontrivial survey selection effects, because they make use of the density of stars in phase space. Large-scale spectroscopic surveys now supply information beyond kinematics in the form of precise stellar label measurements (especially element abundances). These element abundances are known to correlate with orbital actions or other dynamical invariants. Here, we use the Orbital Torus Imaging framework that uses abundance gradients in phase space to map orbits. In many cases these gradients can be measured without detailed knowledge of the selection function. We use stellar surface abundances from the Apache Point Observatory Galactic Evolution Experiment survey combined with kinematic data from the Gaia mission. Our method reveals the vertical (z-direction) orbital structure in the Galaxy and enables empirical measurements of the vertical acceleration field and orbital frequencies in the disk. From these measurements, we infer the total surface mass density, Σ, and midplane volume density, ρ 0, as a function of Galactocentric radius and height. Around the Sun, we find Σ⊙(z=1.1kpc)=72−9+6M⊙pc−2 and ρ⊙(z=0)=0.081−0.009+0.015M⊙pc−3 using the most constraining abundance ratio, [Mg/Fe]. This corresponds to a dark matter contribution in surface density of Σ⊙,DM(z = 1.1 kpc) = 24 ± 4 M ⊙ pc−2, and in total volume mass density of ρ ⊙,DM(z = 0) = 0.011 ± 0.002 M ⊙ pc−3. Moreover, using these mass density values we estimate the scale length of the low-α disk to be h R = 2.24 ± 0.06 kpc.

The Orbital Structure and Selection Effects of the Galactic Center S-star Cluster

The orbital distribution of the S-star cluster surrounding the supermassive black hole in the center of the Milky Way is analyzed. A tight dependence of the pericenter distance r p on orbital eccentricity e ⋆ is found, log(rp)∼(1−e⋆) , which cannot be explained simply by a random distribution of semimajor axis and eccentricities. No stars are found in the region with high e ⋆ and large log(rp) or in the region with low e ⋆ and small log(rp) . Although the sample is still small, the G-clouds show a very similar distribution. The likelihood P(log(rp),(1−e⋆)) to determine the orbital parameters of S-stars is determined. P is very small for stars with large e ⋆ and large log(rp) . S-stars might exist in this region. To determine their orbital parameters, one however needs observations over a longer time period. On the other hand, if stars would exist in the region of low log(rp) and small e ⋆, their orbital parameters should by now have been determined. That this region is unpopulated therefore indicates that no S-stars exist with these orbital characteristics, providing constraints for their formation. We call this region, defined by log(rp/AU)<1.57+2.6(1−e⋆) , the zone of avoidance. Finally, it is shown that the observed frequency of eccentricities and pericenter distances is consistent with a random sampling of log(rp) and e ⋆ if one takes into account the fact that no stars exist in the zone of avoidance and that orbital parameters cannot yet be determined for stars with large r p and large e ⋆.

Congenital Monocular Deficit of Elevation and Myopia Case Report

We present a case of congenital restrictive strabismus and axial myopia that was associated with an anomalous orbital structure identified by MRI and CT. This fibrous band was observed and resected during surgery

Risk Factors for Orbital Invasion in Malignant Eyelid Tumors, Is Orbital Exenteration Still Necessary?

Basal cell carcinoma is the most common malignant skin tumor of the eyelids in Caucasians, followed by squamous cell carcinoma and sebaceous gland carcinoma. The primary treatment for these tumors is radical excision. In cases where malignant eyelid tumors are advanced and have invaded the orbit, orbital exenteration is necessary. In this retrospective study, we aimed to determine the correlation between the risk of orbital infiltration and various factors like tumor location, size, histological type, and patient age. This study revealed that tumors in multiple regions increased the risk of orbital infiltration by 3.75 times. Tumors with a diameter of 21–30 mm raised the likelihood of requiring exenteration by 15.5 times compared to smaller tumors (up to 10 mm). Age was also associated with the likelihood of orbital invasion in periocular tumors. Interestingly, no correlation was found between the histological type of the tumor and the risk of orbital infiltration. Notably, the conjunctiva of the eyeball was the most commonly infiltrated orbital structure, followed by the orbital fat. Timely treatment and well-planned procedures are crucial for patients with malignant periocular skin tumors to avoid multiple reoperations and the potential need for orbital exenteration.

Universal orbital and magnetic structures in infinite-layer nickelates

Universal orbital and magnetic structures in infinite-layer nickelates

Whole-orbit radiomics: machine learning-based multi- and fused- region radiomics signatures for intravenous glucocorticoid response prediction in thyroid eye disease

BackgroundRadiomics analysis of orbital magnetic resonance imaging (MRI) shows preliminary potential for intravenous glucocorticoid (IVGC) response prediction of thyroid eye disease (TED). The current region of interest segmentation contains only a single organ as extraocular muscles (EOMs). It would be of great value to consider all orbital soft tissues and construct a better prediction model.MethodsIn this retrospective study, we enrolled 127 patients with TED that received 4·5 g IVGC therapy and had complete follow-up examinations. Pre-treatment orbital T2-weighted imaging (T2WI) was acquired for all subjects. Using multi-organ segmentation (MOS) strategy, we contoured the EOMs, lacrimal gland (LG), orbital fat (OF), and optic nerve (ON), respectively. By fused-organ segmentation (FOS), we contoured the aforementioned structures as a cohesive unit. Whole-orbit radiomics (WOR) models consisting of a multi-regional radiomics (MRR) model and a fused-regional radiomics (FRR) model were further constructed using six machine learning (ML) algorithms.ResultsThe support vector machine (SVM) classifier had the best performance on the MRR model (AUC = 0·961). The MRR model outperformed the single-regional radiomics (SRR) models (highest AUC = 0·766, XGBoost on EOMs, or LR on OF) and conventional semiquantitative imaging model (highest AUC = 0·760, NaiveBayes). The application of different ML algorithms for the comparison between the MRR model and the FRR model (highest AUC = 0·916, LR) led to different conclusions.ConclusionsThe WOR models achieved a satisfactory result in IVGC response prediction of TED. It would be beneficial to include more orbital structures and implement ML algorithms while constructing radiomics models. The selection of separate or overall segmentation of orbital soft tissues has not yet attained its final optimal result.

Rare-earth Element-based Electrocatalysts Designed for CO2 Electro-reduction.

Electrochemical CO2 reduction presents a promising approach for synthesizing fuels and chemical feedstocks using renewable energy sources. Although significant advancements have been made in the design of catalysts for CO2 reduction reaction (CO2RR) in recent years, the linear scaling relationship of key intermediates, selectivity, stability, and economical efficiency are still required to be improved. Rare earth (RE) elements, recognized as pivotal components in various industrial applications, have been widely used in catalysis due to their unique properties such as redox characteristics, orbital structure, oxygen affinity, large ion radius, and electronic configuration. Furthermore, RE elements could effectively modulate the adsorption strength of intermediates and provide abundant metal active sites for CO2RR. Despite their potential, there is still a shortage of comprehensive and systematic analysis of RE elements employed in the design of electrocatalysts of CO2RR. Therefore, the current approaches for the design of RE element-based electrocatalysts and their applications in CO2RR are thoroughly summarized in this review. The review starts by outlining the characteristics of CO2RR and RE elements, followed by a summary of design strategies and synthetic methods for RE element-based electrocatalysts. Finally, an overview of current limitations in research and an outline of the prospects for future investigations are proposed.

Breed-Specific Skull Morphology Reveals Insights into Canine Optic Chiasm Positioning and Orbital Structure through 3D CT Scan Analysis.

This study's CT scan-based morphometric analysis of 50 adult dogs explored the relationship between skull shape variations (determined by the skull index, SI), optic chiasm, optic canals, and orbital shape. Dogs were classified as brachycephalic (SI ≥ 59), mesocephalic (SI ≥ 51 but <59), and dolichocephalic (SI < 51). No significant age or weight differences were observed. Skull lengths (brachycephalic: 11.39 ± 1.76 cm, mesocephalic: 15.00 ± 2.96 cm, dolichocephalic: 17.96 ± 3.44 cm) and facial lengths (brachycephalic: 3.63 ± 1.00 cm, mesocephalic: 6.46 ± 1.55 cm, dolichocephalic: 8.23 ± 1.03 cm) varied significantly, with shorter orbital depths (brachycephalic: 2.58 ± 0.42 cm, mesocephalic: 3.19 ± 0.65 cm, dolichocephalic: 3.61 ± 0.77 cm) in brachycephalic dogs. The optic chiasm-to-inion horizontal length ratio to cranial horizontal length positively correlated with the SI (r = 0.883, p < 0.001), while the ratio to neurocranial length showed no SI correlation (range: 55.5-75.0). Brachycephalic breeds had a significantly wider optic canal angle (93.74 ± 16.00°), along with broader lacrimal-zygomatic and zygomatic frontal process angles. These findings highlight the zygomatic bone's role in influencing breed-specific orbital variations by connecting the face to the neurocranium, projecting the orbital rim outward and forward with facial shortening.

Maxillary Mucormycosis in a Juvenile Diabetic Patient: A Case Report

One of the most fulminant and quickly spreading types of fungal infection, mucormycosis typically starts in the nose and paranasal sinuses after inhaling spores. Orbital and intracranial structures may become infected either directly or through blood vessels, leading to life-threatening complications. This infection most commonly manifests in the rhinomaxillary area, particularly in individuals with immunocompromised conditions like diabetes. Even with appropriate treatment, the disease’s mortality rate can exceed 40%, and it is challenging to detect. The standard treatment plan involves surgical debridement combined with systemically active antifungal medications, depending on the site of infection and risk factors. As a first-line treatment, lipid-based amphotericin B is recommended; however, posaconazole also shows promise. Hereby, the authors present a case report of a 15-year-old male patient with juvenile diabetes mellitus who had been experiencing pain and diffuse swelling in his left malar area for the previous two months. Following a histological analysis and clinical and radiographic evaluation by a multidisciplinary team, the patient was diagnosed with maxillary mucormycosis. Because of the abundant blood supply in the maxillofacial regions; however, more virulent fungi like Mucor can get past this obstacle. The purpose of present article is to show how early detection and treatment of mucormycosis in a young patient could prevent major morbidity and mortality from this potentially fatal illness . Additionally, it aimed to contribute to the local epidemiology of mucormycosis and raise awareness among stakeholders attention to the difficulties in treating this serious condition.

Analysis of bonding motifs in unusual molecules I: planar hexacoordinated carbon atoms.

The bonding structures of CO3Li3+ and CS3Li3+ are studied by means of oriented quasi-atomic orbitals (QUAOs) to assess the possibility of these molecules being planar hexacoordinated carbon (phC) systems. CH3Li and CO32- are employed as reference molecules. It is found that the introduction of Li+ ions into the molecular environment of carbonate has a greater effect on the orbital structure of the O atoms than it does on the C atom. Partial charges computed from QUAO populations imply repulsion between the positively charged C and Li atoms in CO3Li3+. Upon the transition from CO3Li3+ to CS3Li3+, the analysis reveals that the substitution of O atoms by S atoms inverts the polarity of the carbon-chalcogen σ bond. This is linked to the difference in s- and p-fractions of the QUAOs of C and S, as element electronegativities do not explain the observed polarity of the CSσ bond. Partial charges indicate that the larger electron population on the C atom in CS3Li3+ makes C-Li attraction possible. Upon comparison with the C-Li bond in methyllithium, it is found that the C-Li covalent interactions in CO3Li3+ and CS3Li3+ have about 14% and 6% of the strength of the C-Li covalent interaction in CH3Li, respectively. Consequently, it is concluded that only CS3Li3+ may be considered to be a phC system.

Orbital Structure Involvement in Midface Fractures Impacting Ocular Injury at a Tertiary Hospital in Eastern Indonesia

ABSTRACT Introduction: The midface is a complex anatomical area consisting of several areas. Although various factors protect the eye from trauma, such as orbital rim, blink reflex, elasticity of ocular structures, and protective eye movements by hands and head, ocular injuries remain common in patients with midface fractures, with an incidence rate of up to 90.6%. This study, the first of its kind conducted in Indonesia, aims to evaluate the characteristics and incidence of ocular injuries in midface fractures and to examine the relationship between the treatment. Methods: This observational analytic study employed a retrospective cohort design, utilizing medical record data of midface fracture patients. The independent variables included age, sex, cause, incidence, segment and severity of ocular injury, number of orbital wall involvements, and treatment options. The dependent variable was midface fracture patients. The Mann–Whitney and Fisher’s exact tests were employed to analyze the multivariate data. Results: Individuals aged 32–37 were most commonly affected due to accidents, with the anterior ocular segment and maxilla bone frequently affected. There are no special factors that differentiate a person from experiencing an ocular injury in a midface fracture (P &gt; 0.05). Ocular injuries correlated with orbital wall injury (P = 0.008) at least one discontinuity. Impaired functions included movement and visual disturbances, diplopia, and dystopia (P = 0.134). Conclusions: No significant relationship was found between age, sex, and cause of trauma with ocular injuries in patients with midface fractures. However, a significant relationship was observed between the amount of orbital rim involvement and at least one wall discontinuity occurring in midface fracture patients.

B[double bond, length as m-dash]P double bonds relieved from steric encumbrance: matrix-isolation infrared spectroscopy of the phosphaborene F2B-P[double bond, length as m-dash]BF and the triradical B[double bond, length as m-dash]PF3.

Free phosphaborenes have a labile boron-phosphorus double bond and therefore require extensive steric shielding by bulky substituents to prevent isomerisation and oligomerisation. In the present work, the small free phosphaborene F2B-P[double bond, length as m-dash]BF was isolated by matrix-isolation techniques and was characterised by infrared spectroscopy in conjunction with quantum-chemical methods. In contrast to its sterically hindered relatives, this small phosphaborene exhibits an acute BPB angle of 83° at the CCSD(T) level. An alternative orbital structure for the B[double bond, length as m-dash]P double bond is found in the triradical B[double bond, length as m-dash]PF3, the direct adduct of laser-ablated atomic B and PF3. The single-bonded isomer F2B-PF and the dimer F3P-B[triple bond, length as m-dash]B-PF3 are also tentatively assigned.

Rare earth oxide based electrocatalysts: synthesis, properties and applications.

As an important strategic resource, rare earths (REs) constitute 17 elements in the periodic table, namely 15 lanthanides (Ln) (La-Lu, atomic numbers from 57 to 71), scandium (Sc, atomic number 21) and yttrium (Y, atomic number 39). In the field of catalysis, the localization and incomplete filling of 4f electrons endow REs with unique physical and chemical properties, including rich electronic energy level structures, variable coordination numbers, etc., making them have great potential in electrocatalysis. Among various RE catalytic materials, rare earth oxide (REO)-based electrocatalysts exhibit excellent performances in electrocatalytic reactions due to their simple preparation process and strong structural variability. At the same time, the electronic orbital structure of REs exhibits excellent electron transfer ability, which can reduce the band gap and energy barrier values of rate-determining steps, further accelerating the electron transfer in the electrocatalytic reaction process; however, there is a lack of systematic review of recent advances in REO-based electrocatalysis. This review systematically summarizes the synthesis, properties and applications of REO-based nanocatalysts and discusses their applications in electrocatalysis in detail. It includes the hydrogen evolution reaction (HER), oxygen evolution reaction (OER), hydrogen oxidation reaction (HOR), oxygen reduction reaction (ORR), carbon dioxide reduction reaction (CO2RR), methanol oxidation reaction (MOR), nitrogen reduction reaction (NRR) and other electrocatalytic reactions and further discusses the catalytic mechanism of REs in the above reactions. This review provides a timely and comprehensive summary of the current progress in the application of RE-based nanomaterials in electrocatalytic reactions and provides reasonable prospects for future electrocatalytic applications of REO-based materials.

Synthesis and Some Electrochemical Properties of Carbazole Derivative Monomers for Optoelectronic Device Design

Low-cost instruments are used to achieve high sensitivity, accuracy and precision with electrochemical techniques, making them the most suitable analytical methods used to investigate the electrochemical properties of a new molecule. Among these techniques, cyclic voltammetry, which is widely employed, allows for the determination of electronic characteristics such as molecular energy levels and orbital structure, redox properties, sensor capabilities, surface activity, and more. The carbazole molecule can undergo derivatization from various positions, allowing for alterations in its electrical and optical properties. These compounds serve as heterocyclic building blocks that can be utilized as materials for organic sensitizers and semiconductors in optoelectronic devices. Due to the presence of a hydrogen atom in the nitrogen-hydrogen (N-H) bond within the carbazole structure, which can be replaced with different functional groups, carbazole is highly suitable for nitrogen-based derivatization studies. In this study, two different carbazole monomers (IIa and IIIa), which could be potential optoelectronic, were synthesized using the Ullman and Suzuki-Miyaura reaction and characterized using 1H NMR, 13C NMR, UV-Vis, and Flouresence spectroscopy techniques. The cyclic voltammetry experiments were performed using three different working electrodes (Au, Gc, Pt disk electrodes) for each compound. Since the optimum oxidation of the compounds was obtained from the voltammograms on the gold disk electrode, this electrode was used in the calculation of energy levels. HOMO and Eg values of the compounds were deduced from cyclic voltammetry experiments and the optical absorption bands, respectively.

Enhanced Redox Electrocatalysis in High-Entropy Perovskite Fluorides by Tailoring d–p Hybridization

HighlightsThe tailored KCoMnNiMgZnF3-HEC cathode delivers extremely high discharge capacity (22,104 mAh g−1), outstanding long-term cyclability (over 500 h), preceding majority of traditional catalysts reported.Entropy effect of multiple sites in KCoMnNiMgZnF3-HEC engenders appropriate regulation of 3d orbital structure, leading to a moderate hybridization with the p orbital of key intermediate.The homogeneous nucleation of Li2O2 is achieved on multiple cation site, contributing to effective mass transfer at the three-phase interface, and thus, the reversibility of O2/Li2O2 conversion.

Novel incision to debulk eyelids in a case of Orbital Periorbital Plexiform Neurofibroma (OPPN): A case report

: Plexiform neurofibroma with neurofibromatosis 1 is a autosomal dominant condition and a relatively rare condition. It is also termed as Von Recklinghausen disease. PN involving the structures like eyelid, orbit, periorbital and facial structures are labelled as orbital-periorbital PN(OPPN). These are slowly progressing lesions and are present since birth but increase in size during childhood and are locally infiltrating in nature.: To describe a lid incision to simultaneously debulk both upper and lower eyelid, preserving the vascularity in a case of Orbital Periorbital Plexiform Neurofibroma (OPPN).: We report a case of 22 year male who presented with a disfiguring swelling of right side of face since childhood. After thorough clinical and radiological evaluation it was diagnosed to be a OPPN. Staged debulking was planned and after stage 1 debulking, tissue was sent for HPE which revealed overgrowth of peripheral nerve components and connective tissue dermis showing infiltrating tumour composed of oval to spindle cells with pleomorphic nuclei and moderate cytoplasm. Staged debulking with lid reduction surgery was performed.: Neurofibroma is a rare entity with plexiform neurofibroma occurring in 5-15% of patients. OPPN infiltrates locally without respecting the anatomical planes but follows the trigeminal nerve distribution usually. Indications for debulking procedure are usually the disfigurement and optimal timing is also not certain because the extent and rate of growth cannot be predicted.: The facial appearance and outcome in patients with OPPN can be significantly improved through lid reduction surgery.

A Unique Case of Primary Subfrontal Lobe Meningioma with Intraorbital Extension

Introduction: Meningiomas, tumors originating from the meninges covering the brain, are typically considered benign. They primarily develop from arachnoid cap cells within the meninges and can manifest as primary orbital meningiomas (affecting structures like the optic nerve sheath) or secondary orbital meningiomas that extend from intracranial origins, such as the sphenoid wing and rarely from frontal lobe as in our case. Case Presentation: This report documents a very rare case where a meningioma emerged in the subfrontal lobe of the brain and subsequently spread to the orbit. The presence of such malignant variants in the orbit poses unique diagnostic challenges due to their potential to compress critical adjacent brain structures. Impact on Orbital Structures: The extension of these tumors into the orbit can have significant consequences, affecting structures like the cavernous sinus, superior orbital fissure, intraorbital contents, and the optic nerve. This further complicates their surgical management, given their proximity to essential neurological systems. Conclusion: This case study underscores the atypical growth pattern of malignant meningioma and highlights the complexities associated with identifying and treating meningioma with orbital extensions. The propensity of these tumors to impact vital brain structures necessitates a comprehensive approach to their diagnosis and management.

Layer-Structured Multitransition-Metal Oxide Cathode Materials for Potassium-Ion Batteries with Long Cycling Lifespan and Superior Rate Capability.

Manganese (Mn)-based layer-structured transition metal oxides are considered as excellent cathode materials for potassium ion batteries (KIBs) owing to their low theoretical cost and high voltage plateau. The energy density and cycling lifetime, however, cannot simultaneously satisfy the basic requirements of the market for energy storage systems. One of the primary causes results from the complex structural transformation and transition metal migration during the ion intercalation and deintercalation process. The orbital and electronic structure of the octahedral center metal element plays an important role for maintaining the octahedral structural integrity and improving the K+ diffusivity by the introduced heterogeneous [Me-O] chemical bonding. A multitransition metal oxide, P3-type K0.5Mn0.85Co0.05Fe0.05Al0.05O2 (KMCFAO), was synthesized and employed as a cathode material for KIBs. Beneficial from the larger layer spacing for K+ to better accommodate and effectively preventing the irreversible structural transformation in the insertion/extraction process, it can reach a superior capacity retention up to 96.8% after 300 cycles at a current density of 500 mA g-1. The full cell of KMCFAO//hard carbon exhibits an encouraging promising energy density of 113.8 W h kg-1 at 100 mA g-1 and a capacity retention of 72.6% for 500 cycles.

The behaviour of a forced spherical pendulum operating in a weightless environment

Summary In this article, we show that by subjecting the pivot of a simple inextensible pendulum to small amplitude high frequency rectilinear oscillations it is possible to make it operate in a weightless environment. The axis of vibration of the pivot defines a preferred direction in space and a consequential dynamical structure which is completely absent when the pivot is fixed. Using spherical polar coordinates centred at the pivot, we show that the motion of such a pendulum has fast and slow-scale components which we analyse using the method of multiple scales. The slow scale equation for the polar angle is autonomous, and a phase plane analysis reveals the essential orbital structure including the existence of conical solutions analogous to the terrestrial fixed pivot conical pendulum. In the absence of an azimuthal velocity component, its behaviour can provide a direct simulation of a plane terrestrial simple fixed pivot pendulum with a correspondingly simple form for the small amplitude period. We can also use a two-scale analysis to examine the effects of damping. Here, the slow scale polar equation has two asymptotically stable states, and we employ a combination of numerical and asymptotic analyses to elicit the slow scale orbital trajectories.