A proposed novel digital condylar position adjustment technique to help restore a normal disc-condyle relationship.

Objectives: To demonstrate a novel digital technique that enables real-time visualisation of occlusal transfer and adjustment of condyle position, to (1) improve the repeatability of occlusal transfer and the accuracy of condyle position adjustment and (2) be clinically effective in helping to restore the disc-condyle relationship. Materials and methods: Three participants were included in the study and underwent facebow transfers using two different methods. The digital method used patient-related three-dimensional imaging data matched with digital dental casts for occlusal transfer. The conventional method used anatomical facebows. The condylar position was adjusted based on occlusal transfer results. The results were evaluated and compared in three dimensions. In addition, clinical application data from 36 patients were analysed before and after condylar position adjustment. Statistical significance was set at p < 0.05. Results: Differences in the spatial positions of the three anatomical structures reproduced by both methods were statistically significant (p = 0.000). After adjusting the rotation of the condylar position, the positional deviation of the condylar point along the X- and Z-axes was significantly lower in the digital group (p < 0.05). After adjustment for translation (X and Z), the positional deviation showed no difference along the X- and Z-axes (p > 0.05) but a significant difference along the Y-axis (p < 0.001). Conclusion: A novel digital technique for occlusal transfer and condylar position adjustment was presented. This technique simplifies clinical practice, improves the accuracy of results, and can help restore a normal disc-condyle relationship.

Effect of occlusal contact on TMJ loading during occlusion: An in silico study.

Alterations in occlusal features may have significant consequences, ranging from dental aesthetics to health issues. Temporomandibular joint disorders (TMDs) are often associated with joint overload, and the correlation between occlusal features and TMDs has been thoroughly discussed. In current work, we introduced a novel stomatognathic model that aligns well with in vivo experimental measurements, specifically designed to decouple the impact of occlusal contact and periodontal ligament (PDL) negative feedback on temporomandibular joint (TMJ) loading. Utilizing an in-silico approach, the simulation analysis included six symmetric occlusal contact scenarios. Furthermore, a biomechanical lever model was employed to clarify the mechanical mechanism and investigate the multi-factorial effects of TMJ overload. These findings indicate that anterior shifts in the occlusal centre lead to increased TMJ loading, particularly in occlusal contact cases with anteroposterior changes. Considering the symmetrical distribution of occlusal contact, mediolateral alterations had a more modest effect on TMJ loading. Additionally, potential negative feedback activated by principal strain of periodontal could not only alleviate joint load but also diminish occlusal force. These investigations enhance our understanding of the intricate interactions between masticatory muscles, occlusal forces, and joint contact forces, thereby providing motivation for future comprehensive studies on TMJ biomechanical overload.

Effect of the application of digital technology-assisted optimization in the process of adjusting jaw position.

OBJECTIVES: The aim of this study was to demonstrate a novel jaw position adjustment technique derived from digital twins and evaluate the application effect of digital technology-assisted optimization in the process of adjusting jaw position on patients with temporomandibular disorders (TMD). METHODS: A total of 74 patients with TMD who attended the Department of Temporomandibular Joint, West China Hospital of Stomatology, Si-chuan University, between June 2022 and May 2023 were selected. The patient's initial computed tomography (CT) and bilateral temporomandibular joint data obtained by magnetic resonance imaging (MRI) were collected. The 148 joints were divided into the normal disc-condyle relationship (N) group, disc displacement with reduction (DDWR) group, and disc displacement without reduction (DDWoR) group. Assisted by digital technology, the patient's CT data were reconstructed, and a personalized reference plane was established to adjust the jaw position. A three-point bite guiding splint was designed by the adjusted occlusal space and then fabricated by 3D printing technology. It was worn by the patients and then reviewed by MRI. Before and after the adjustment of jaw position, the amount and direction of condyle and disc displacement and the angle between condyle and disc were measured as the evaluation indexes of the effect of the adjustment. The correlation with condylar displacement was evaluated. RESULTS: In the N group, the disc moved backward and downward along the X and Z axes by (-0.60±0.62) and (0.51±0.71) mm, respectively. In the DDWR group, the disc moved backward and upward along the X and Z axes by (-1.33±1.38) and (-0.09±1.31) mm, respectively. In the DDWoR group, the disc moved forward and downward along the X and Z axes by (0.49±1.76) and (1.35±1.76) mm, respectively. The angle between the condyle and the disc decreased after adjustment of the jaw position in all three groups. All patients showed improvement in symptoms after adjustment. CONCLUSIONS: Digital technology-assisted jaw position adjustment can simplify the process, reduce the sensitivity of the technique, and improve patients' disc-condyle structure and symptoms. Therefore, its application in the treatment of patients with TMD is of great clinical significance.

Relationships between functional temporomandibular joint space and disc morphology, position, and condylar osseous condition in patients with temporomandibular disorder.

OBJECTIVE: To investigate the correlations between joint space and temporomandibular joint (TMJ) components and the compressive states of the disc and condyle subsequent to joint space changes. MATERIALS AND METHODS: A total of 240 TMJs were categorized according to disc morphology, disc position, and condylar osseous condition. The two-dimensional (2D) and three-dimensional (3D) measurements were compared. The functional joint space (FJS) and disc areas on closed- and open-mouth images (DA-C and DA-O) were also calculated, and the joint space was measured in five directions. Different groups of TMJ components were compared. A spring model was used to simulate the effect of condylar displacement on the disc and condyle. RESULTS: Disc morphology was strongly correlated with its position. The measurements were equivalent between 2D and 3D methods. DA-C and FJS differed significantly between groups. The DA-C to FJS ratio differed between the Class 2 and Class 3 groups and between disc displacement groups with and without reduction. Altered disc morphology and position were correlated with significant changes in joint space in the 60°, 90°, and 120° directions. Despite minor discrepancies among condylar osseous conditions, reduced joint space was correlated with bone destruction at the corresponding site. The spring model stimulation revealed that condylar displacement caused elevated stresses on the disc and condyle. CONCLUSIONS: Condylar displacement causes joint space alterations while exerting compressive pressure on both the disc and condyle. CLINICAL RELEVANCE: Proper condylar positioning within the fossa is recommended to ensure sufficient articular disc accommodation.

Three-dimensional theoretical model for effectively describing the effect of craniomaxillofacial structural factors on loading situation in the temporomandibular joint.

BACKGROUND: Temporomandibular joint (TMJ) overloading is considered a primary cause of temporomandibular joint disorders (TMD). Accordingly, craniomaxillofacial structural parameters affect the loading situation in the TMJ. However, no effective method exists for quantitatively measuring the loading variation in human TMJs. Clinical statistics, which draws from general rules from large amounts of clinical data, cannot entry for exploring the underlying biomechanical mechanism in craniomaxillofacial system. The finite element method (FEM) is an effective tool for analyze the stress and load on TMJs for several cases in a short period of time; however, it is difficult to generalize general patterns through calculations between different cases due to the different geometric characteristics and occlusal contacts between each case. METHODS: (1) This study included 88 subjects with 176 unilateral data to measure angle (α) of the distance to the plane of occlusion. The bone destruction score was evaluated for clinical statistics. To rule out effects of the potential factors and ensure the generality of the study, one participant with no obvious bone destruction was selected as the standard case for establishing the three-dimensional (3D) theoretical model and FEM. (2) Three groups of forces, including biting, muscles and joint reaction forces on mandible, were adopted to establish a 3D theoretical model. (3) By modifying the sagittal α and coronal three types of deviation angle (φ) of the original model, nine candidate models were obtained for the FEM studies. RESULTS: (1) The static equilibrium equations, were used to establish a 3D theoretical model for describing the loading of the TMJ. The theoretical model was validated by monotonously modifying the structural parameter in comparison to two-dimensional theoretical models reported previously; (2) The force on the TMJ gradually decreased with α, and this trend was validated by both clinic statistics and FEM results; (3) The effects of the three types of deviation angle were different. The results of the case where only rotating biting forces were considered was consistent with clinical statistics, indicating that the side with lower α experiences higher TMJ load. (4) Changing the unilateral proportionality coefficients of biting and muscle force produced opposite effects, wherein the effects of the muscle force were stronger than those of the biting forces. CONCLUSIONS: A negative correlation was observed between the joint load and α. Among the three types of asymmetric deformities, occlusal deviations were the primary factors leading to TMD. Unilateral occlusion can result in a greater load on the ipsilateral joint and should be avoided when using the side corresponding to the TMD. This study provides a theoretical basis for the biomechanical mechanism of TMD and also enables the targeted mitigation and treatment of TMD through structural modification.

Atomic-scale insights into the interfacial charge transfer in a NiO/CeO2 heterostructure for electrocatalytic hydrogen evolution.

To understand the underlying mechanism of the interfacial charge transfer and local chemical state variation in the nonprecious-based hydrogen evolution reaction (HER) electrocatalysts, a model system of the NiO/CeO2 heterostructure was chosen for investigation using a combination of the advanced electron microscopic characterization and first-principles calculations. The results directly proved that interfacial charge transfer occurs from Ni to Ce, leading to reduction in the valence state of Ce and increased formation of VO. This would optimize ΔGH* and facilitate the hydrogen evolution process, resulting in outstanding HER performance in 1 M KOH with a low overpotential of 99 mV at the current density of 10 mA•cm-2 and a modest Tafel slope of 78.4 mV•dec-1 for the NiO/CeO2 heterostructure sample. Therefore, the improved HER performance could be attributed to the synergistic coupling interactions and electron redistribution at the interface of NiO and CeO2. These results concretely demonstrate the direct determination of the interfacial structure of the heterostructure and provide atomistic insights to unravel the underlying mechanism of interfacial charge transfer induced HER performance improvement.

Variation in stress distribution modified by mandibular material property: a 3D finite element analysis.

BACKGROUND: Temporomandibular joint disorder (TMD) is a common oral and maxillary facial disease. Finite element method (FEM) has been widely used in TMD studies. Material assignment significantly affects FEM results. The differences in the methods of material assignment used in previous studies have not been comprehensively assessed for further calculations. METHODS: The mandible material modelling approaches were of four types, namely: uniform modelling with (A) cortical bone; and (B) cancellous bone; (C) semi-uniform modelling with division of cortical and cancellous bone; and (D) non-uniform modelling with Computed tomography (CT) gray value related modulus. Meanwhile, the Young's modulus of values ranging from 20 to 300 GPa were considered for the teeth. Ten modellings were used to analyze and discuss the differences in contact pressure and contact force. RESULTS: (1) The increase in teeth elastic modulus increased the maximum contact pressure on the alveolar bone and contact force on teeth, but induced insignificant stress variation on the temporomandibular joint; (2) The location of the maximum contact pressure was steady for all four modelling approaches of the mandibular material. However, the maximum contact pressure and contact force exhibited an insignificant difference. CONCLUSIONS: Teeth with a higher elastic modulus significantly enhanced the stress concentration in the alveolar bone; in contrast, it induced minor variations in the temporomandibular joint stress states. The extreme stress regions predicted by the four mandibular models were consistent with the actual damaged regions. However, non-uniform modellings based on CT values could better describe the mechanical properties of the human bone, which should be primarily considered.

Atomic-Scale Insights into the Interfacial Polarization Effect in the InGaN/GaN Heterostructure for Solar Cells.

The model system of the InGaN/GaN quantum wells (QWs), based on the first principles calculation, was chosen to understand the underlying mechanism of interfacial polarization and its synergic effect with the built-in electric field (Bef) at the p-n junction in solar cells (SLs). The polarized electric field (Pef) was generated due to the redistribution of electrons and holes at the interface; moreover, the Pef of InGaN/GaN heterostructure on the semipolar (01-11) GaN surface was consistent with that of on the N-polar (000-1) surface, which is on the lines of the Bef and favors the electron-hole separation efficiency in SLs. Furthermore, the growth of high-quality InGaN/GaN QWs on the semipolar (01-11) GaN surface was achieved. Such an atomic-scale investigation provides a fundamental understanding of the polarization charge-induced Pef and its interaction coupling with Bef at the p-n junction, which could be generalized to polar material-based SLs.

Condyle bone destruction: the association between temporomandibular joint vibration and finite element analysis.

OBJECTIVE: The objective of the study is to investigate the stress distributions of condyle and articular disc at different mandibular plane angles and the association between the temporomandibular joint (TMJ) vibration and anatomical relationship. SETTING AND SAMPLE POPULATION: Data from 195 untreated patients were analyzed. Patients were, respectively, divided into 3 groups, based on cone-beam computed tomography (CBCT): Group 0 presenting normal condyles, Group 1 presenting mild bone change, and Group 2 presenting severe bone change; based on magnetic resonance imaging (MRI): normal disc position (N), disc displacement with reduction (DDR) and disc displacement without reduction (DDNR); based on the mandibular plane angle: low, normal and high. METHODS: (1) According to peak frequency, average amplitude, and occurrence phase, association was assessed between TMJ condition and TMJ vibration; (2) A three-dimensional finite element model of masticatory system was established and the relationship between mandibular plane angle and condyle bone destruction was described. RESULTS: The average amplitude of TMJ vibration negatively correlated with pathological condition of the articular disc (p < 0.01). The angle of SN-MP was strongly relevant to bone destruction of condyle (p < 0.01), and the biomechanical analysis showed that with the increase of SN-MP angle, the area of stress concentration in the posterior slope of condyle rose. CONCLUSIONS: The average amplitude of TMJ vibration decreased with the pathological position state of articular disc, and condyle bone destruction was positively associated with SN-MP angle.

Spin Polarization-Assisted Dopant Segregation at a Coherent Phase Boundary.

Coherent phase boundaries are widely expected as segregation-free boundaries due to their low interfacial energies and lack of trapping sites for impurities. Here, we report an equilibrium segregation of W atoms at fully coherent terraces of a Fe3O4 (111)/Fe2O3 (0001) phase boundary that was never expected previously. Through comparison of pristine and W-doped Fe3O4/Fe2O3 phase boundaries, it is revealed that the spin polarization of O atoms at the interface plays an important role in the periodic segregation of W atoms. Unusual spin-polarized O atoms with large magnetic moments are periodically arranged in the interfacial O plane of the pristine phase boundary. After doping of W at this boundary, W atoms will selectively substitute the Fe atoms of Fe2O3 that directly bond with three spin-polarized O atoms, thereby resulting in the complete neutralization of the magnetic moments of the spin-polarized O atoms. These findings reveal that coherent phase boundaries are able to trap impurities and local spin polarization is one of the driving forces for dopant segregation, suggesting that elemental doping is an efficient way for tailoring the physical properties of boundaries in magnetic materials and devices.

Anion exchange induced formation of kesterite copper zinc tin sulphide-copper zinc tin selenide nanoheterostructures.

We report the colloidal synthesis of quaternary kesterite CZTS-CZTSe heterostructures via anion exchange reactions on a kesterite CZTS template. The crystal phase selectivity during the synthesis (kesterite vs. wurtzite) is due to the initial nucleation of cubic Cu9S5 seeds, followed by incorporation of Zn and Sn. Upon injection of Se-precursor, which triggered simultaneous anion exchange and overgrowth of the pristine CZTS template, sandwich CZTS-CZTSe (core-tip) nanoheterostructures were obtained. X-ray photoelectron spectroscopy (XPS) and optical band gap measurement results suggest a change of intrinsic electronic structure of CZTS by Se-treatment. Our study not only provides insight into mechanisms of formation of kesterite CZTS nanocrystals (NCs) and subsequent anion exchange reactions, but also opens doors to access novel CZTSSe nanostructures for potential applications.

Binary and Ternary Colloidal Cu-Sn-Te Nanocrystals for Thermoelectric Thin Films.

Recent advances in copper chalcogenide-based nanocrystals (NCs), copper sulfide, and copper selenide derived nanostructures, have drawn considerable attention. However, reports of crystal phase and shape engineering of binary or ternary copper telluride NCs remain rare. Here, a colloidal hot-injection approach for producing binary copper/tin telluride, and ternary copper tin telluride NCs with controllable compositions, crystal structures, and morphologies is reported. The crystal phase and growth behavior of these tellurides are systematically studied from both experimental and theoretical perspectives. The morphology of Cu1.29 Te NCs is modified from 1D nanorods with different aspect ratios to 2D nanosheets and 3D nanocubes, by controlling the preferential growth of specific crystalline facets. A controllable phase transition from Cu1.29 Te to Cu1.43 Te NCs is also demonstrated. The latter can be further converted into Cu2 SnTe3 and SnTe through Sn incorporation. Temperature dependent thermoelectric properties of metal (Cu and Sn) telluride nanostructure thin films are also studied, including Cu1.29 Te, Cu1.43 Te, Cu2 SnTe3 , and SnTe. Cu2 SnTe3 is a low carrier density semimetal with compensating electron and hole Fermi surface pockets. The engineering of crystal phase and morphology control of colloidal copper tin telluride NCs opens a path to explore and design new classes of copper telluride-based nanomaterials for thermoelectrics and other applications.

Detwinning Mechanism for Nanotwinned Cubic Boron Nitride with Unprecedented Strength: A First-Principles Study.

Synthesized nanotwinned cubic boron nitride (nt-cBN) and nanotwinned diamond (nt-diamond) exhibit extremely high hardness and excellent stability, in which nanotwinned structure plays a crucial role. Here we reveal by first-principles calculations a strengthening mechanism of detwinning, which is induced by partial slip on a glide-set plane. We found that continuous partial slip in the nanotwinned structure under large shear strain can effectively delay the structural graphitization and promote the phase transition from twin structure to cubic structure, which helps to increase the maximum strain range and peak stress. Moreover, ab initio molecular dynamics simulation reveals a stabilization mechanism for nanotwin. These results can help us to understand the unprecedented strength and stability arising from the twin boundaries.

Stabilizing the metastable superhard material wurtzite boron nitride by three-dimensional networks of planar defects.

Wurtzite boron nitride (w-BN) is a metastable superhard material that is a high-pressure polymorph of BN. Clarifying how the metastable high-pressure material can be stabilized at atmospheric pressure is a challenging issue of fundamental scientific importance and promising technological value. Here, we fabricate millimeter-size w-BN bulk crystals via the hexagonal-to-wurtzite phase transformation at high pressure and high temperature. By combining transmission electron microscopy and ab initio molecular dynamics simulations, we reveal a stabilization mechanism for w-BN, i.e., the metastable high-pressure phase can be stabilized by 3D networks of planar defects which are constructed by a high density of intersecting (0001) stacking faults and {10[Formula: see text]0} inversion domain boundaries. The 3D networks of planar defects segment the w-BN bulk crystal into numerous nanometer-size prismatic domains with the reverse crystallographic polarities. Our findings unambiguously demonstrate the retarding effect of crystal defects on the phase transformations of metastable materials, which is in contrast to the common knowledge that the crystal defects in materials will facilitate the occurrence of phase transformations.

Ceramic phases with one-dimensional long-range order.

Solids are generally classified into three categories based on their atomic arrangement: crystalline, quasicrystalline and amorphous1-4. Here we report MgO and Nd2O3 ceramic phases with special atomic arrangements that should belong to a category of solids different from these three well known categories by combining state-of-the-art atomic-resolution scanning transmission electron microscopy and first-principles calculations. The reported solid structure exhibits a one-dimensional (1D) long-range order with a translational periodicity and is composed of structural units that individually have atomic arrangements similar to those observed in coincidence-site lattice configurations present at grain boundaries. Regardless of the insulating nature of the bulk MgO, the bandgap of which is measured to be 7.4 eV, the MgO 1D ordered structure is a wide-bandgap semiconductor with a bandgap of 3.2 eV owing to this special atomic arrangement. The discovery of 1D ordered structures suggests that the structural categories of solids could be more abundant, with physical properties distinct from their regular counterparts.

A general and rapid room-temperature synthesis approach for metal sulphide nanocrystals with tunable properties.

Colloidal metal sulphide (MS) nanocrystals (NCs) have recently attracted considerable attention because of their tunable properties that can be exploited in various physical, chemical and biological applications. In this work, we present a novel and general method for synthesis of monodispersed binary (CuS, Ag2S, CdS, PbS, and SnS), ternary (Ag-In-S, Cu-In-S and Cu-Sn-S) and quaternary (Cu-Zn-Sn-S) MS NCs. The synthesis is conducted at room temperature, with an immediate crystallization process and up to 60 seconds of growth time, enabling rapid synthesis without external heating. For some of the ternary and quaternary NCs produced with relatively low crystallinity, we then carried out a "colloidal annealing" process to improve their crystallinity without changing their composition. Moreover, we show that the morphology and optical properties of the NCs can be tuned by varying the concentration of precursors and reaction time. The shape evolution and photoluminescence of particular MS NCs were also studied. These results not only provide insights into the growth mechanisms of MS NCs, but also yield a generalized, low cost, and potentially scalable method to fabricate them.

Higher Strength and Ductility than Diamond: Nanotwinned Diamond/Cubic Boron Nitride Multilayer.

Recently, the nanotwinned structure has attracted considerable attention because of unprecedented improvement in its mechanical properties, thermal stability, and other properties. Here, we introduce the nanotwinned structure between two superhard materials [diamond and cubic boron nitride (cBN)] and obtain a nanotwinned diamond/cBN multilayered material with ultrahigh strength and unprecedented ductility. Under continuous shear deformation, the stress and total energy in the material develop in a zigzag way because of atomic reconfiguration. Further research shows that atomic reconfiguration occurs preferentially in the cBN region, followed by that in the diamond region by partial slip, and finally occurs at the interface through alternate "exchange" of the positions of C and B atoms. This multilevel stress release model can account for the significant increase in the strain range and peak stress of nanotwinned materials. These results could provide available information for the design of superhard materials with multilevel resistance to plastic deformation.

Direct Imaging for Single Molecular Chain of Surfactant on CeO2 Nanocrystals.

Organic surfactant controls the synthesis of nanocrystals (NCs) with uniform size and morphology by attaching on the surface of NCs and further facilitates their assembly into ordered superstructure, which produces versatile functional nanomaterials for practical applications. It is essential to directly resolve the surfactant molecules on the surface of NCs to improve the understanding of surface chemistry of NCs. However, the imaging resolution and contrast are insufficient for a single molecule of organic surfactant on NCs. In this work, direct characterization of organic surfactant on CeO2 NCs is conducted by using the state-of-the-art aberration corrected scanning transmission electron microscopy (STEM) imaging and electron energy loss spectra (EELS) techniques. The explicit evidence for the existence and distribution of organic surfactant on CeO2 NCs are obtained on the atomic scale by EELS elemental mapping. Besides, STEM imaging parameters are systematically adjusted and optimized for the direct imaging of a single molecular chain of organic surfactant on CeO2 NCs. Such direct visualization of organic surfactant molecule on the surface of NCs can be a significant step forward in the fields of nanomaterials surface chemistry and materials characterization.

Controllable Colloidal Synthesis of Tin(II) Chalcogenide Nanocrystals and Their Solution-Processed Flexible Thermoelectric Thin Films.

A systematic colloidal synthesis approach to prepare tin(II, IV) chalcogenide nanocrystals with controllable valence and morphology is reported, and the preparation of solution-processed nanostructured thermoelectric thin films from them is then demonstrated. Triangular SnS nanoplates with a recently-reported π-cubic structure, SnSe with various shapes (nanostars and both rectangular and hexagonal nanoplates), SnTe nanorods, and previously reported Sn(IV) chalcogenides, are obtained using different combinations of solvents and ligands with an Sn4+ precursor. These unique nanostructures and the lattice defects associated with their Sn-rich composition allow the production of flexible thin films with competitive thermoelectric performance, exhibiting room temperature Seebeck coefficients of 115, 81, and 153 µV K-1 for SnS, SnSe, and SnTe films, respectively. Interestingly, a p-type to n-type transition is observed in SnS and SnSe due to partial anion loss during post-synthesis annealing at 500 °C. A maximum figure of merit (ZT) value of 0.183 is achieved for an SnTe thin film at 500 K, exceeding ZT values from previous reports on SnTe at this temperature. Thus, a general strategy to prepare tin(II) chalcogenide nanocrystals is provided, and their potential for use in high-performance flexible thin film thermoelectric generators is demonstrated.

Selective Cation Incorporation into Copper Sulfide Based Nanoheterostructures.

Heterogeneous copper sulfide based nanostructures have attracted intense attention based on their potential to combine the plasmonic properties of copper-deficient copper sulfides with properties of other semiconductors and metals. In general, copper sulfides are versatile platforms for production of other materials by cation incorporation and exchange processes. However, the outcomes of subsequent cation exchange (CE) or incorporation processes involving nanoheterostructure (NH) templates have not been explored. In this work, we incorporate indium and tin into Cu1.81S-ZnS NHs. We demonstrate that the outcomes of cation incorporation are strongly influenced by heterocation identity and valence and by the presence of a Cu-extracting agent. The selectivity of cation incorporation depends upon both the cation itself and the heterodomains in which CE reactions take place. The final nanocrystals (NCs) emerge in many forms including homogeneous NCs, heterodimers, core@shell NHs and NHs with three different domains. This selective cation incorporation not only facilitates the preparation of previously unavailable metal sulfide NHs but also provides insight into mechanisms of CE reactions.