ABSTRACT
Two-dimensional electrides can acquire topologically non-trivial phases due to intriguing interplay between the cationic atomic layers and anionic electron layers. However, experimental evidence of topological surface states has yet to be verified. Here, via angle-resolved photoemission spectroscopy (ARPES) and scanning tunnelling microscopy (STM), we probe the magnetic Weyl states of the ferromagnetic electride [Gd2C]2+·2e-. In particular, the presence of Weyl cones and Fermi-arc states is demonstrated through photon energy-dependent ARPES measurements, agreeing with theoretical band structure calculations. Notably, the STM measurements reveal that the Fermi-arc states exist underneath a floating quantum electron liquid on the top Gd layer, forming double-stacked surface states in a heterostructure. Our work thus not only unveils the non-trivial topology of the [Gd2C]2+·2e- electride but also realizes a surface heterostructure that can host phenomena distinct from the bulk.
ABSTRACT
In 2D noble metals like copper, the carrier scattering at grain boundaries has obscured the intrinsic nature of electronic transport. However, it is demonstrated that the intrinsic nature of transport by hole carriers in 2D copper can be revealed by growing thin films without grain boundaries. As even a slight deviation from the twin boundary is perceived as grain boundaries by electrons, it is only through the thorough elimination of grain boundaries that the hidden hole-like attribute of 2D single-crystal copper can be unmasked. Two types of Fermi surfaces, a large hexagonal Fermi surface centered at the zone center and the triangular Fermi surface around the zone corner, tightly matching to the calculated Fermi surface topology, confirmed by angle-resolved photoemission spectroscopy (ARPES) measurements and vivid nonlinear Hall effects of the 2D single-crystal copper account for the presence of hole carriers experimentally. This breakthrough suggests the potential to manipulate the majority carrier polarity in metals by means of grain boundary engineering in a 2D geometry.
ABSTRACT
In this comprehensive investigation, we explore the effectiveness of 55 dual-atom catalysts (DACs) supported on graphitic carbon nitride (gCN) for both alkaline and acidic hydrogen evolution reactions (HER). Employing density functional theory (DFT), we scrutinize the thermodynamic and kinetic profiles of these DACs, revealing their considerable potential across a diverse pH spectrum. For acidic HER, our results identify catalysts such as FePd-gCN, CrCr-gCN, and NiPd-gCN, displaying promising ΔGH* values of 0.0, 0.0, and -0.15 eV, respectively. This highlights their potential effectiveness in acidic environments, thereby expanding the scope of their applicability. Within the domain of alkaline HER, this study delves into the thermodynamic and kinetic profiles of DACs supported on gCN, utilizing DFT to illuminate their efficacy in alkaline HER. Through systematic evaluation, we identify that DACs such as CrCo-gCN, FeRu-gCN, and FeIr-gCN not only demonstrate favorable Gibbs free energy change (ΔGmax) for the overall water splitting reaction of 0.02, 0.27, and 0.38 eV, respectively, but also feature low activation energies (Ea) for water dissociation, with CrCo-gCN, FeRu-gCN, and FeIr-gCN notably exhibiting the Ea of just 0.42, 0.33, and 0.42 eV, respectively. The introduction of an electronic descriptor (φ), derived from d electron count (Nd) and electronegativity (ETM), provides a quantifiable relationship with catalytic activity, where a lower φ corresponds to enhanced reaction kinetics. Specifically, φ values between 4.0-4.6 correlate with the lowest kinetic barriers, signifying a streamlined HER process. Our findings suggest that DACs with optimized φ values present a robust approach for the development of high-performance alkaline HER electrocatalysts, offering a pathway towards the rational design of energy-efficient catalytic systems.
ABSTRACT
It is known that many diabetic patients experience testicular atrophy. This study sought to investigate the effect of 4-hexylresorcinol (4HR) on testicular function in rats with streptozotocin (STZ)-induced diabetes, focusing on testicular weight, sperm motility, histological alterations, and serum testosterone levels to understand the efficacy of 4HR on testes. Our findings reveal that 4HR treatment significantly improves testicular health in diabetic rats. Notably, the STZ group exhibited a testicular weight of 1.22 ± 0.48 g, whereas the STZ/4HR group showed a significantly enhanced weight of 1.91 ± 0.26 g (p < 0.001), aligning closely with the control group's weight of 1.99 ± 0.17 g and the 4HR group's weight of 2.05 ± 0.24 g, indicating no significant difference between control and 4HR groups (p > 0.05). Furthermore, the STZ/4HR group demonstrated significantly improved sperm motility compared to the STZ group, with apoptotic indicators notably reduced in the STZ/4HR group relative to the STZ group (p < 0.05). These results underscore the therapeutic potential of 4HR for maintaining testicular function under diabetic conditions.
Subject(s)
Diabetes Mellitus, Experimental , Hexylresorcinol , Sperm Motility , Testis , Testosterone , Animals , Male , Diabetes Mellitus, Experimental/drug therapy , Testis/drug effects , Testis/metabolism , Testis/pathology , Rats , Sperm Motility/drug effects , Testosterone/blood , Hexylresorcinol/pharmacology , Hexylresorcinol/therapeutic use , Apoptosis/drug effects , Streptozocin , Rats, Sprague-Dawley , Organ Size/drug effectsABSTRACT
This narrative review systematically explores the progression of materials and techniques in alveolar ridge preservation (ARP). We commence by delineating the evolution from traditional ARP methods to cutting-edge alternatives, including platelet-rich fibrin, injectable bone repair materials, and hydrogel systems. Critical examination of various studies reveals these innovative approaches not only accelerate bone healing but also significantly improve patient-reported outcomes, such as satisfaction, pain perception, and overall quality of life. Emphasis is placed on the correlation between advanced ARP techniques and enhanced patient comfort and clinical efficacy, underscoring their transformative potential in dental implantology. Highlighting the effectiveness of ARP, the implant survival rate over a span of 5 to 7 years was high, showcasing the reliability and success of these methods. Further, patients expressed high aesthetic satisfaction with the soft tissue outcome, evidenced by an average visual analog scale (VAS) score of 94. This positive aesthetic appraisal is linked to the clinical health of implants, potentially due to the employment of tooth-supported surgical guides. The economic analysis reveals a varied cost range for bone graft substitutes ($46.2 to $140) and socket sealing materials ($12 to $189), with a noteworthy correlation between the investment in barrier membranes and the diminished horizontal and vertical ridge resorption. This suggests that membrane usage significantly contributes to preserving ridge dimensions, offering a cost-effective strategy for enhancing ARP outcomes. In conclusion, this review illuminates the significant advancements in ARP, highlighting the shift towards innovative materials and techniques that not only promise enhanced bone regeneration and reduced healing times but also improve patient satisfaction and aesthetic outcomes. The documented high implant survival rate and the beneficial economic implications of membrane use further validate the effectiveness of contemporary ARP strategies, paving the way for their broader adoption in dental implantology.
ABSTRACT
Orthognathic surgery, essential for addressing jaw and facial skeletal irregularities, has historically relied on traditional surgical planning (TSP) involving a series of time-consuming steps including two-dimensional radiographs. The advent of virtual surgical planning (VSP) and 3D printing technologies has revolutionized this field, bringing unprecedented precision and customization to surgical processes. VSP facilitates 3D visualization of the surgical site, allowing for real-time adjustments and improving preoperative stress for patients by reducing planning time. 3D printing dovetails with VSP, offering the creation of anatomical models and surgical guides, enhancing the predictability of surgical outcomes despite higher initial setup and material costs. The integration of VSP and 3D printing promises innovative and effective solutions in orthognathic surgery, surpassing the limitations of traditional methods. Patient-reported outcomes show a positive post-surgery impact on the quality of life, underlining the significant role of these technologies in enhancing self-esteem and reducing anxiety. Economic analyses depict a promising long-term fiscal advantage with these modern technologies, notwithstanding the higher initial costs. The review emphasizes the need for large-scale randomized controlled trials to address existing research gaps and calls for a deeper exploration into the long-term impacts and ethical considerations of these technologies. In conclusion, while standing on the cusp of a technological renaissance in orthognathic surgery, it is incumbent upon the medical fraternity to foster a collaborative approach, balancing innovation with scrutiny to enhance patient care. The narrative review encourages the leveraging of VSP and 3D printing technologies for more efficient and patient-centric orthognathic surgery, urging the community to navigate uncharted territories in pursuit of precision and efficiency in the surgical landscape.
ABSTRACT
The complex process of bone regeneration is influenced by factors such as inflammatory responses, tissue interactions, and progenitor cells. Currently, multiple traumas can interfere with fracture healing, causing the prolonging or failure of healing. In these cases, bone grafting is the most effective treatment. However, there are several drawbacks, such as morbidity at the donor site and availability of suitable materials. Advantages have been provided in this field by a variety of stem cell types. Adipose-derived stem cells (ASCs) show promise. In the radiological examination of this study, it was confirmed that the C/S group showed faster regeneration than the other groups, and Micro-CT also showed that the degree of bone formation in the defect area was highest in the C/S group. Compared to the control group, the change in cortical bone area in the defect area decreased in the sham group (0.874), while it slightly increased in the C/S group (1.027). An increase in relative vascularity indicates a decrease in overall bone density, but a weak depression filled with fibrous tissue was observed outside the compact bone. It was confirmed that newly formed cortical bone showed a slight difference in bone density compared to surrounding normal bone tissue due to increased distribution of cortical bone. In this study, we investigated the effect of bone regeneration by ADMSCs measured by radiation and pathological effects. These data can ultimately be applied to humans with important clinical applications in various bone diseases, regenerative, and early stages of formative differentiation.
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Objective: : To investigate the long-term effects of 4-hexylresorcinol (4HR) on facial skeletal growth in growing male rats, with a focus on diabetic animal models. Methods: : Forty male rats were used. Of them, type 1 diabetes mellitus was induced in 20 animals by administering 40 mg/kg streptozotocin (STZ), and they were assigned to either the STZ or 4HR-injected group (STZ/4HR group). The remaining 20 healthy rats were divided into control and 4HR groups. We administered 4HR subcutaneously at a weekly dose of 10 mg/kg until the rats were euthanized. At 16 weeks of age, whole blood was collected, and micro-computed tomography of the skull and femur was performed. Results: : All craniofacial linear measurements were smaller in the STZ group than in the control group. The mandibular molar width was significantly smaller in the 4HR group than in the control group (P = 0.031) but larger in the STZ/4HR group than in the STZ group (P = 0.011). Among the diabetic animals, the STZ/4HR group exhibited significantly greater cortical bone thickness, bone mineral density, and bone volume than the STZ group. Serum testosterone levels were also significantly higher in the STZ/4HR group than in the STZ group. Conclusions: : 4HR administration may have divergent effects on mandibular growth and bone mass in healthy and diabetic rats. In the context of diabetes, 4HR appears to have beneficial effects, potentially through the modulation of mitochondrial respiration.
ABSTRACT
Density functional theory (DFT) calculations were utilized to investigate the electrocatalytic potential of single boron (B) atom doping in defective ReS2 monolayers as an active site. Our investigation revealed that B-doped defective ReS2, containing S and S-Re-S defects, demonstrated remarkable conductivity, and emerged as an exceptionally active catalyst for nitrogen reduction reactions (NRR), exhibiting limiting potentials of 0.63 and 0.53 V, respectively. For both cases, we determined the potential by examining the hydrogenation of adsorbed N2* to N2H*. Although the competing hydrogen evolution reaction (HER) process appeared dominant in the S-Re-S defect case, its impact was minimal. The outstanding NRR performance can be ascribed to the robust chemical interactions between B and N atoms. The adsorption of N2 on B weakens the N-N bond, thereby facilitating the formation of NH3. Moreover, we verified the selectivity and stability of the catalysts for NRR. Our findings indicate that B-doped defective ReS2 monolayers hold considerable promise for electrocatalysis in a variety of applications.
ABSTRACT
Fluorescent dyes have garnered significant attention as theranostic platforms owing to their inherent characteristics. In this study, we present the discovery of Medical Fluorophore 33 (MF33), a novel and potent theranostic agent with a phenaleno-isoquinolinium salt structure that can serve as a cancer therapeutic strategy. The synthesis of MF33 is readily achievable through a simple Rh(III)-catalyzed reaction. Moreover, MF33 displayed strong fluorescence signals, excellent microsomal stability, and high biocompatibility in vivo. It induces significant apoptosis in cancer cells via the p53/p21/caspase-3 signaling pathway, leading to selective cytotoxicity in various cancer cells. In vivo fluorescence imaging with MF33 enabled the visualization of sentinel lymph nodes in living mice. Notably, repeated intraperitoneal administration of MF33 resulted in antitumor activity in mice with colorectal cancer. Collectively, our findings suggest that phenaleno-isoquinolinium salt-based MF33 is a viable theranostic agent for biomedical imaging and cancer treatment.
Subject(s)
Fluorescent Dyes , Neoplasms , Animals , Mice , Fluorescent Dyes/chemistry , Precision Medicine , Feasibility Studies , Neoplasms/therapy , Theranostic Nanomedicine/methodsABSTRACT
A 75-year-old male patient visited Gangneung-Wonju National University Dental Hospital (Gangneung, South Korea) with a 35-mm fluctuant lesion on the floor of the mouth. It was a dome-shaped exophytic lesion with its top on Wharton's duct orifice area. The encapsulated lesion was excised cautiously and the final diagnosis was non-infiltrating angiolipoma. To the best of our knowledge, this is the first report of an intraoral approach for the treatment of a non-infiltrating angiolipoma on the floor of the mouth in an elderly patient. Differentiating it from a ranula is essential for the surgical approach and, as there is a higher transition to infiltrating angiolipoma, definite treatment should be considered in elderly patients.
ABSTRACT
The potential of sericin, a protein derived from silkworms, is explored in bone graft applications. Sericin's biocompatibility, hydrophilic nature, and cost-effectiveness make it a promising candidate for enhancing traditional graft materials. Its antioxidant, anti-inflammatory, and UV-resistant properties contribute to a healthier bone-healing environment, and its incorporation into 3D-printed grafts could lead to personalized medical solutions. However, despite these promising attributes, there are still gaps in our understanding. The precise mechanism through which sericin influences bone cell growth and healing is not fully understood, and more comprehensive clinical trials are needed to confirm its long-term biocompatibility in humans. Furthermore, the best methods for incorporating sericin into existing graft materials are still under investigation, and potential allergic reactions or immune responses to sericin need further study.
ABSTRACT
Copper surfaces that exhibit a wide range of achromatic colors while still metallic have not been studied, despite advancements in antireflection coatings. A series of achromatic copper films grown with [111] preferred orientation by depositing 3D porous nanostructures is introduced via coherent/incoherent atomic sputtering epitaxy. The porous copper nanostructures self-regulate the giant oxidation resistance by constructing a curved surface that generates a series of monoatomic steps, followed by shrinkage of the lattice spacing of one or two surface layers. First-principles calculations confirm that these structural components cooperatively increase the energy barrier against oxygen penetration. The achromaticity of the single-crystalline porous copper films is systematically tuned by geometrical parameters such as pore size distribution and 3D linkage. The optimized achromatic copper films with high oxidation resistance show an unusual switching effect between superhydrophilicity and superhydrophobicity. The tailored 3D porous nanostructures can be a candidate material for numerous applications, such as antireflection coatings, microfluidic devices, droplet tweezers, and reversible wettability switches.
ABSTRACT
Graphdiyne (GDY), a new 2D material, has recently proven excellent performance in photodetector applications due to its direct bandgap and high mobility. Different from the zero-gap of graphene, these preeminent properties made GDY emerge as a rising star for solving the bottleneck of graphene-based inefficient heterojunction. Herein, a highly effective graphdiyne/molybdenum (GDY/MoS2 ) type-II heterojunction in a charge separation is reported toward a high-performance photodetector. Characterized by robust electron repulsion of alkyne-rich skeleton, the GDY based junction facilitates the effective electron-hole pairs separation and transfer. This results in significant suppression of Auger recombination up to six times at the GDY/MoS2 interface compared with the pristine materials owing to an ultrafast hot hole transfer from MoS2 to GDY. GDY/MoS2 device demonstrates notable photovoltaic behavior with a short-circuit current of -1.3 × 10-5 A and a large open-circuit voltage of 0.23 V under visible irradiation. As a positive-charge-attracting magnet, under illumination, alkyne-rich framework induces positive photogating effect on the neighboring MoS2 , further enhancing photocurrent. Consequently, the device exhibits broadband detection (453-1064 nm) with a maximum responsivity of 78.5 A W-1 and a high speed of 50 µs. Results open up a new promising strategy using GDY toward effective junction for future optoelectronic applications.
ABSTRACT
Constructing a mono-atom step-level ultra-flat material surface is challenging, especially for thin films, because it is prohibitively difficult for trillions of clusters to coherently merge. Even though a rough metal surface, as well as the scattering of carriers at grain boundaries, limits electron transport and obscures their intrinsic properties, the importance of the flat surface has not been emphasised sufficiently. In this study, we describe in detail the initial growth of copper thin films required for mono-atom step-level flat surfaces (MSFSs). Deposition using atomic sputtering epitaxy leads to the coherent merging of trillions of islands into a coplanar layer, eventually forming an MSFS, for which the key factor is suggested to be the individual deposition of single atoms. Theoretical calculations support that single sputtered atoms ensure the formation of highly aligned nanodroplets and help them to merge into a coplanar layer. The realisation of the ultra-flat surfaces is expected to greatly assist efforts to improve quantum behaviour by increasing the coherency of electrons.
ABSTRACT
BACKGROUND: Silk sericin is an active ingredient in bone grafts. However, the optimal scaffold for silk sericin has yet to be identified. METHOD: A critical-sized bone defect model in rat calvaria was used to evaluate bone regeneration. Silk sericin from Yeonnokjam, Bombyx mori, was incorporated into gelatin (group G, n = 6) and collagen (group C, n = 6). Bone regeneration was evaluated using micro-computed tomography (mCT) and histology. RESULTS: Group C showed a larger bone volume than group G in the mCT analysis (P = 0.001). Histological analysis showed a larger area of bony defects in group G than in group C. The bone regeneration area in group C was significantly larger than that in group G (P = 0.003). CONCLUSION: Compared with gelatin, collagen shows better bone regeneration in silk sericin-based bone grafts.