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We investigated temperature (T) and excitation density dependent ultrafast near-infrared (NIR) transient reflectivity dynamics in the charge density wave (CDW) phases of bulk layered 1T-VSe2 using NIR and visible excitations. The data reveal fingerprints of conventional non-adiabatic CDW collective dynamics with rather fast electronic order parameter dynamics showing sub-picosecond suppression and recovery. The slower T-dependent 100-ps dynamics indicates rather isotropic heat transport dominated by the lattice degrees of freedom. [ABSTRACT FROM AUTHOR]

The interaction of electrons with the lattice in metals can lead to reduction of their kinetic energy to the point where they may form heavy, dressed quasiparticles—polarons. Unfortunately, polaronic lattice distortions are difficult to distinguish from more conventional charge- and spin-ordering phenomena at low temperatures. Here we present a study of local symmetry breaking of the lattice structure on the picosecond timescale in the prototype layered dichalcogenide Mott insulator 1T-TaS2 using X-ray pair-distribution function measurements. We clearly identify symmetry-breaking polaronic lattice distortions at temperatures well above the ordered phases, and record the evolution of broken symmetry states from 915 K to 15 K. The data imply that charge ordering is driven by polaron crystallization into a Wigner crystal-like state, rather than Fermi surface nesting or conventional electron-phonon coupling. At intermediate temperatures the local lattice distortions are found to be consistent with a quantum spin liquid state. The layered material 1T-TaS2 continues to attract attention due to its many correlated phases and metastable states. Bozin et al. report persistent symmetry-breaking polaronic distortions in the wide range of temperatures, which has implications for understanding the mechanisms of charge and spin ordered states. [ABSTRACT FROM AUTHOR]

Background/Aim. Surgical extraction of impacted lower third molars is inevitably followed by the postoperative occurrence of trismus, swelling, and pain sensations to some degree. Corticosteroids (dexamethasone in particular) are commonly used drugs in the prevention of these complications. The aim of this study was to determine the effectiveness of dexamethasone in the prevention of postoperative complications, edema, trismus, and pain after the surgical extraction of impacted lower third molars, depending on the method of its administration. Methods. This prospective study involved 30 healthy patients, aged 18 years and above, of both sexes, with fully impacted lower third molar – class I or II and position B or C, according to Pell and Gregory classification system and vertical position according to Winter classification. All patients were divided randomly into three groups de-pending on the way of dexamethasone administration: oral – dexamethasone administered in the form of oral tablets in a dose of 4 mg one hour before the surgery; submucosal – dexamethasone solution administered submucosally in a dose of 4 mg in the area of the buccal sulcus, after the inferior alveolar nerve block anesthesia and additional anesthesia for the buccal nerve; intramuscular – dexamethasone solution administered intramuscularly in a dose of 4mg into the area of the deltoid muscle, right before the intervention. Preoperatively and at every follow-up (on the first, second, and seventh day postoperatively), interincisal distance, the degree of edema, and the level of pain with the use of a visual analog scale (VAS) were measured. On the seventh postoperative day, the total number of analgesics taken by the patients was recorded. Results. In the postoperative period, there was no statistically significant difference be-tween the examined groups in terms of effectiveness in swelling, trismus, and pain reduction (p > 0.05). Conclusion. There is no significant difference in dexamethasone effectiveness in postoperative trismus, swelling, and pain reduction after the third lower molar surgery, regarding the route of administration – oral, intramuscular, or local submucosal.

Background/Aim: The objective of the study was to compare cytological diagnoses using transepithelial cytology (oral brush biopsy) with histopathological diagnoses obtained by incisional biopsy in patients with benign lesions, oral potentially malignant disorders and oral squamous cell carcinoma. Material and Methods: The study included 57 patients. Brush biopsy was performed after local anaesthesia administration using the cervical brush. It was immediately followed by an incisional biopsy. Modified Bethesda System was used for cytological analysis and correlated with histopathological diagnoses according to intraepithelial neoplasia. Results: Good agreement was shown between cytological and histopathological diagnosis (kappa = 0.791). The sensitivity of the study was 92.85%, specificity 100%, positive predictive value (PPV) was 100% and negative predictive value (NPV) 93.54%. Conclusions: Oral brush biopsy, which allows the collection of epithelial cells of all layers can provide fast, precise and efficient cytological results which are in good agreement with the 'gold standard' - incisional biopsy followed by histopathology.

Objectives: To study the correlation between positive cochlin tomoprotein testing (CTP), magnetic resonance (MR) imaging, and the auditory and vestibular function amongst patients with sudden hearing loss., Study Design: Prospective case series., Methods: We prospectively examined eight patients who presented with sudden hearing loss (>60 dB) with or without vertigo or tinnitus. We performed an ELISA-based CTP detection test using middle ear lavage samples. In addition to the CTP examination, a magnetic resonance imaging (MRI) examination was performed using different sequences (T1 and a T1 sequence with a contrast medium (CM), a T2 sequence, 4 h delayed intravenous gadolinium-enhanced three-dimensional fluid-attenuated inversion recovery (3D FLAIR))., Results: All patients with sudden hearing loss (>60 dB) presented a non-specific contrast enhancement in the cochlea and vestibulum on the affected side on delayed 3D-FLAIR MRI. Four patients had a positive CTP test, suggesting a perilymphatic fistula (PLF). However, no specific MRI signal for a PLF was observed., Conclusions: Using multimodal diagnostic measures, such as CTP testing and different MRI sequences, no correlation could be found in patients with a PLF.

Relaxation dynamics of complex many-body quantum systems trapped into metastable states is a very active field of research from both the theoretical and experimental point of view with implications in a wide array of topics from macroscopic quantum tunnelling and nucleosynthesis to non-equilibrium superconductivity and energy-efficient memory devices. In this work, we investigate quantum domain reconfiguration dynamics in the electronic superlattice of a quantum material using time-resolved scanning tunneling microscopy and unveil a crossover from temperature to noisy quantum fluctuation dominated dynamics. The process is modeled using a programmable superconducting quantum annealer in which qubit interconnections correspond directly to the microscopic interactions between electrons in the quantum material. Crucially, the dynamics of both the experiment and quantum simulation is driven by spectrally similar pink noise. We find that the simulations reproduce the emergent time evolution and temperature dependence of the experimentally observed electronic domain dynamics., (© 2024. The Author(s).)

Metastability of many-body quantum states is rare and still poorly understood. An exceptional example is the low-temperature metallic state of the layered dichalcogenide 1T-TaS 2 in which electronic order is frozen after external excitation. Here we visualize the microscopic dynamics of injected charges in the metastable state using a multiple-tip scanning tunnelling microscope. We observe non-thermal formation of a metastable network of dislocations interconnected by domain walls, that leads to macroscopic robustness of the state to external thermal perturbations, such as small applied currents. With higher currents, we observe annihilation of dislocations following topological rules, accompanied with a change of macroscopic electrical resistance. Modelling carrier injection into a Wigner crystal reveals the origin of formation of fractionalized, topologically entangled networks, which defines the spatial fabric through which single particle excitations propagate. The possibility of manipulating topological entanglement of such networks suggests the way forward in the search for elusive metastable states in quantum many body systems., (© 2023. The Author(s).)

Metastable phases present a promising route to expand the functionality of complex materials. Of particular interest are light-induced metastable phases that are inaccessible under equilibrium conditions, as they often host new, emergent properties switchable on ultrafast timescales. However, the processes governing the trajectories to such hidden phases remain largely unexplored. Here, using time- and angle-resolved photoemission spectroscopy, we investigate the ultrafast dynamics of the formation of a hidden quantum state in the layered dichalcogenide 1 T -TaS 2 upon photoexcitation. Our results reveal the nonthermal character of the transition governed by a collective charge-density-wave excitation. Using a double-pulse excitation of the structural mode, we show vibrational coherent control of the phase-transition efficiency. Our demonstration of exceptional control, switching speed, and stability of the hidden state are key for device applications at the nexus of electronics and photonics.

Placing quantum materials into optical cavities provides a unique platform for controlling quantum cooperative properties of matter, by both weak and strong light-matter coupling 1,2 . Here we report experimental evidence of reversible cavity control of a metal-to-insulator phase transition in a correlated solid-state material. We embed the charge density wave material 1T-TaS 2 into cryogenic tunable terahertz cavities 3 and show that a switch between conductive and insulating behaviours, associated with a large change in the sample temperature, is obtained by mechanically tuning the distance between the cavity mirrors and their alignment. The large thermal modification observed is indicative of a Purcell-like scenario in which the spectral profile of the cavity modifies the energy exchange between the material and the external electromagnetic field. Our findings provide opportunities for controlling the thermodynamics and macroscopic transport properties of quantum materials by engineering their electromagnetic environment., (© 2023. The Author(s), under exclusive licence to Springer Nature Limited.)

Oral microbiome disruptions in periodontitis are related to the chronic inflammatory reactions that could in turn lead to the development of multiple oral diseases. The objective of the study was to assess the frequencies of Streptococcus mitis , Prevotella melaninogenica , and Prevotella intermedia in oral benign lesions, oral potentially malignant disorders (OPMDs), and oral squamous cell carcinomas (OSCCs) and investigate the impact of these bacteria on the expression patterns of the selected (potential) target genes ( PI3CA / AKT2 / mTOR , DUSP16 / MAPK14 , and COX2 ). After sample collection (25 benign lesions, 30 OPMDs, and 35 OSCCs) and DNA/RNA extraction, quantitative real-time polymerase chain reaction (qPCR) was performed to detect bacterial presence and assess relative gene expression levels in different lesion groups. Prevotella melaninogenica was the most prevalent of the three analyzed bacteria, with the frequency being 60% in benign lesions, 87% in OPMDs ( p = 0.024), and 77% in OSCC. The OPMD tissues in which Prevotella melaninogenica was present exhibited a higher expression level of AKT2 ( p = 0.042). Significantly lower expression of DUSP16 was observed in OSCC tissues containing Streptococcus mitis ( p = 0.011). The obtained results indicate a substantial contribution of P. melaninogenica and Str. mitis in the pathogenesis of oral mucosal lesions, possibly via AKT2 upregulation and DUSP16 downregulation.

We report an experimental approach to produce spatially localized photoinduced superconducting state in a cuprate superconductor using optical vortices with ultrafast pulses. The measurements were carried out using coaxially aligned three-pulse time-resolved spectroscopy, in which an intense vortex pulse was used for coherent quenching of superconductivity and the resulting spatially modulated metastable states were analyzed by the pump-probe spectroscopy. The transient response after quenching shows a spatially localized superconducting state that remains unquenched at the dark core of the vortex beam for a few picoseconds. Because the quenching is instantaneously driven by photoexcited quasiparticles, the vortex beam profile can be transferred directly to the electron system. By using the optical vortex-induced superconductor, we demonstrate spatially resolved imaging of the superconducting response and show that the spatial resolution can be improved using the same principle as that of super-resolution microscopy for fluorescent molecules. The demonstration of spatially controlled photoinduced superconductivity is significant for establishing a new method for exploring novel photoinduced phenomena and applications in ultrafast optical devices.

Current trends in data processing have given impetus for an intense search of new concepts of memory devices with emphasis on efficiency, speed, and scalability. A promising new approach to memory storage is based on resistance switching between charge-ordered domain states in the layered dichalcogenide 1T-TaS 2 . Here we investigate the energy efficiency scaling of such charge configuration memory (CCM) devices as a function of device size and data write time τ W as well as other parameters that have bearing on efficient device operation. We find that switching energy efficiency scales approximately linearly with both quantities over multiple decades, departing from linearity only when τ W approaches the ∼0.5 ps intrinsic switching limit. Compared to current state of the art memory devices, CCM devices are found to be much faster and significantly more energy efficient, demonstrated here with two-terminal switching using 2.2 fJ, 16 ps electrical pulses.