Programmable Colloids with Analogous Hypercoordination Complex Architectures

Colloidal molecule clusters (CMCs) are promising building blocks with molecule-like symmetry, offering exceptional synergistic properties for applications in plasmonics and catalysis. Traditional CMC fabrication has been limited to simple molecule-like structures utilizing isotropic particles. Here, we employ molecular dynamics simulation to investigate the co-assembly of anisotropic nanorods (NRs) and the stimulus-responsive polymer (SRP) via reversible adsorption. The results of the simulation show that it is possible to fabricate hypercoordination complex structures with high symmetry from the co-assembly of NRs and the SRP, even in analogy to the Th(BH4)4 structure. The coordination number of these CMCs can be precisely programmed by adjusting the shape and size of the ends of the NRs and the SRP cohesion energy. Furthermore, a finite-difference time-domain simulation indicates these hypercoordination structures exhibit significantly enhanced optical activity and plasmonic coupling effects. These findings introduce a new design approach for complex molecule-like structures utilizing anisotropic nanoparticles and may expand the applications of CMCs in photonics.

Ultrasmall Single-Chain Nanoparticles Derived from Amphiphilic Alternating Copolymers

The collapse or folding of an individual polymer chain into a nanoscale particle gives rise to single-chain nanoparticles (SCNPs), which share a soft nature with biological protein particles. The precise control of their properties, including morphology, internal structure, size, and deformability, are a long-standing and challenging pursuit. Herein, a new strategy based on amphiphilic alternating copolymers for producing SCNPs with ultrasmall size and uniform structure is presented. SCNPs are obtained by folding the designed alternating copolymer in N,N-dimethylformamide (DMF) and fixing it through a photocatalyzed cycloaddition reaction of anthracene units. Molecular dynamics simulation confirms the solvophilic outer corona and solvophobic inner core structure of SCNPs. Furthermore, by adjusting the length of PEG units, precise control over the mean size of SCNPs is achieved within the range of 2.8 to 3.9 nm. These findings highlight a new synthetic strategy that enables enhanced control over morphology and internal structure while achieving ultrasmall and uniform size for SCNPs.

Chemically Specific Systematic Coarse-Grained Polymer Model with Both Consistently Structural and Dynamical Properties

The coarse-grained (CG) model serves as a powerful tool for the simulation of polymer systems; its reliability depends on the accurate representation of both structural and dynamical properties. However, strong correlations between structural and dynamical properties on different scales and also a strong memory effect, enforced by chain connectivity between monomers in polymer systems, render developing a chemically specific systematic CG model a formidable task. In this study, we report a systematic CG approach that combines the iterative Boltzmann inversion (IBI) method and the generalized Langevin equation (GLE) dynamics. Structural properties are ensured by using conservative CG potentials derived from the IBI method. To retrieve the correct dynamical properties in the system, we demonstrate that using a combination of a Rouse-type delta function and a time-dependent short-time kernel in the GLE simulation is practically efficient. The former can be used to adjust the long-time diffusion dynamics, and the latter can be reconstructed from an iterative procedure according to the velocity autocorrelation function (ACF) from all-atomistic (AA) simulations. Taking the polystyrene as an example, we show that not only structural properties of radial distribution function, intramolecular bond, and angle distributions can be reproduced but also dynamical properties of mean-square displacement, velocity ACF, and force ACF resulted from our CG model have quantitative agreement with the reference AA model. In addition, reasonable agreements are observed in other collective properties between our GLE-CG model and the AA simulations as well.

Exploring the interplay of liquid crystal orientation and spherical elastic shell deformation in spatial confinement

The application of liquid crystal technology typically relies on the precise control of molecular orientation at a surface or interface. This control can be achieved through a combination of morphological and chemical methods. Consequently, variations in constrained boundary flexibility can result in a diverse range of phase behaviors. In this study, we delve into the self-assembly of liquid crystals within elastic spatial confinement by using the Gay-Berne model with the aid of molecular dynamics simulations. Our findings reveal that a spherical elastic shell promotes a more regular and orderly alignment of liquid crystals compared to a hard shell. Moreover, during the cooling process, the hard-shell confined system undergoes an isotropic-smectic phase transition. In contrast, the phase behavior within the spherical elastic shell closely mirrors the isotropic-nematic-smectic phase transition observed in bulk systems. This indicates that the orientational arrangement of liquid crystals and the deformations induced by a flexible interface engage in a competitive interplay during the self-assembly process. Importantly, we found that phase behavior could be manipulated by altering the flexibility of the confined boundaries. This insight offers a fresh perspective for the design of innovative materials, particularly in the realm of liquid crystal/polymer composites.

Horizontal to perpendicular transition of lamellar and cylinder phases in block copolymer films induced by interface segregation of single-chain nanoparticles during solvent evaporation

How to fabricate perpendicularly oriented domains (PODs) of lamellar and cylinder phases in block copolymer thin films remains a major challenge. In this work, via a coarse-grained molecular dynamics simulation study, we report a solvent evaporation strategy starting from a mixed solution of A-b-B-type diblock copolymers (DBCs) and single-chain nanoparticles (SCNPs) with the same composition, which is capable of spontaneously generating PODs in drying DBC films induced by the interface segregation of SCNPs. The latter occurs at both the free surface and substrate and, consequently, neutralizes the interface selectivity of distinct blocks in DBCs, leading to spontaneous formation of PODs at both interfaces. The interface segregation of SCNPs is related to the weak solvophilicity of the internal cross-linker units. A mean-field theory calculation demonstrates that the increase in the chemical potential of SCNPs in the bulk region drives their interface segregation along with solvent evaporation. We believe that such a strategy can be useful in regulating the PODs of DBC films in practical applications.

Molecular Origin of the Reinforcement Effect and Its Strain-Rate Dependence in Polymer Nanocomposite Glass

We investigate the molecular origin of mechanical reinforcement in a polymer nanocomposite (PNC) under a glass state via molecular dynamics simulations. The strength of the PNC system is found to be reinforced mainly via reduced plastic deformations of the nanoparticle neighborhood (NN). Such a reinforcement effect is found to decay with an increase in the strain rate. The Arrhenius-Eyring relation is used to analyze its origin. The amplitude of the reinforcement is found to be determined by the difference between the energy barrier (ΔE) for the activation of NN and the work (W) done by the applied stress to conquer that barrier. A larger strain rate is found to result in a larger W and, hence, a weaker reinforcement effect. Such a strain-rate dependence is verified in the experimental tensile tests of a poly(vinyl alcohol)/SiO2 composite system. These results not only provide a new understanding of the molecular origin of the reinforcement effect in the PNC system, but also pave the way for a better design of the PNC material properties.

Nanoscopic Characterization Reveals that Bulk Amorphous Elementary Boron Is Composed of a Ladder-like Polymer with B4 as the Structural Unit

As the initially discovered allotrope of boron, amorphous elementary boron (AE-B) has been reported for more than two centuries. Several possible structures of AE-B have been proposed during the past decades. Due to its noncrystalline nature, however, the structure of AE-B has not yet been determined. We notice that AE-B can be dissolved in organic solvents, although the solubility is very low. After surface adsorption from solution, the individual or the self-assembled structure of AE-B molecules can be characterized at the single-molecule or nanoscopic level, which may be helpful to reveal the molecular structure of AE-B. Atomic force microscopy (AFM) imaging shows that AE-B is a chain-like molecule with a thickness (or height) of 0.17 ± 0.01 nm, which agrees well with the diameter of a B atom, demonstrating that the structure of an AE-B molecule contains only one layer of B atoms. Results from high-resolution transmission electron microscopy (HRTEM) indicate that AE-B molecules can be self-assembled into a nanosheet with parallel lines. The width of each line is 0.27 nm, and the periodical length along the chain axial direction is 0.32 ± 0.01 nm. These results indicate that AE-B is composed of a ladder-like inorganic polymer with B₄ as the structural unit. This conclusion is supported by the single-chain elasticity obtained by single-molecule AFM and quantum mechanical calculations. We expect that this fundamental study is not only an ending of the two-century-old scientific mystery but also the beginning of the research and applications of AE-B (ladder B) as a polymeric material. The research strategy may be also used to study other amorphous inorganic materials.

Automatic Multiscale Method of Building up a Cross-linked Polymer Reaction System: Bridging SMILES to the Multiscale Molecular Dynamics Simulation

An automatic method is introduced to generate the initial configuration and input file from SMILES for multiscale molecular dynamics (MD) simulation of cross-linked polymer reaction systems. Inputs are a modified version of SMILES of all the components and conditions of coarse-grained (CG) and all-atom (AA) simulations. The overall process comprises the following steps: (1) Modified SMILES inputs of all the components are converted to 3-dimensional coordinates of molecular structures. (2) Molecular structures are mapped to the coarse-grained scale, followed by a CG reaction simulation. (3) CG beads are backmapped to the atomic scale after the CG reaction. (4) An AA productive run is finally performed to analyze volume shrinkage, glass transition, and atomic detail of network structure. The method is applied to two common epoxy resin reactions, that is, the cross-linking process of DGEVA (diglycidyl ether of vanillyl alcohol) and DHAVA (dihydroxyaminopropane of vanillyl alcohol) and that of DGEBA (diglycidyl ether of bisphenol A) and DETA (diethylenetriamine). These components form network structures after the CG cross-linking reaction and are then backmapped to calculate properties in the atomic scale. The result demonstrates that the method can accurately predict volume shrinkage, glass transition, and all-atom structure of cross-linked polymers. The method bridges from SMILES to MD simulation trajectories in an automatic way, which shortens the time of building up cross-linked polymer reaction model and suitable for high-throughput computations.

Janus polymer-grafted nanoparticles mimicking membrane repair proteins for the prevention of lipid membrane rupture

Plasma membrane rupture often leads to cell damage, especially when there is a lack of membrane repair proteins near the wounds due to genetic mutations in organisms. To efficiently promote the repair of the injured lipid membrane, nanomedicines may act as a promising alternative to membrane repair proteins, but the related research is still in its infancy. Herein, using dissipative particle dynamics simulations, we designed a class of Janus polymer-grafted nanoparticles (PGNPs) that can mimic the function of membrane repair proteins. The Janus PGNPs comprise both hydrophobic and hydrophilic polymer chains grafted on nanoparticles (NPs). We track the dynamic process of the adsorption of Janus PGNPs at the damaged site in the lipid membrane and systematically assess the driving forces for this process. Our results reveal that tuning the length of the grafted polymer chains and the surface polarity of the NPs can efficiently enhance the adsorption of Janus PGNPs at the site of the damaged membrane to reduce membrane stress. After repair, the adsorbed Janus PGNPs can be successfully detached from the membrane, leaving the membrane untouched. These results provide valuable guidelines for designing advanced nanomaterials for the repair of damaged lipid membranes.

[Correlation between balloon volume and Meckel's cave size and its influence of percutaneous microballoon compression for trigeminal neuralgia]

Objective: To investigate the correlation between balloon volume and Meckel's cave size during percutaneous puncture microballoon compression (PMC) for trigeminal neuralgia and the influence of the compression coefficient (the ratio of balloon volume/Meckel's cave size) on the prognosis. Methods: Seventy-two patients (28 males and 44 females) aged (62±11) years who underwent PMC under general anesthesia for trigeminal neuralgia in the First Affiliated Hospital of Zhengzhou University from February 2018 to October 2020 were retrospectively collected. All patients underwent preoperative cranial magnetic resonance imaging (MRI) to measure Meckel's cave size, intraoperative balloon volume was recorded, and the compression coefficient was calculated. Follow-up visits were performed preoperatively (T₀) and 1 d (T₁), 1 month (T₂), 3 months (T₃), and 6 months (T₄) postoperatively, either in the outpatient clinic or by telephone, and the Barrow Neurological Institute pain scale (BNI-P) score, the Barrow Neurological Institute facial numbness (BNI-N) score and the occurrence of complications were recorded and compared at each time point. Patients were divided into 3 groups according to different prognoses: patients in group A (n=48) were with no recurrence of pain and mild facial numbness, patients in group B (n=19) were with no recurrence of pain but severe facial numbness, while those in group C (n=5) had recurrence of pain. The differences in balloon volume, Meckel's cave size, and compression coefficient were compared among the three groups, and the correlation between balloon volume and Meckel's cave size in each group was analyzed by Pearson correlation. Results: The effective rate of PMC for trigeminal neuralgia was 93.1% (67/72). At time points from T₀ to T₄, patients had BNI-P scores [M (Q₁, Q₃)] of 4.5 (4.0, 5.0), 1.0 (1.0, 1.0), 1.0 (1.0, 1.0), 1.0 (1.0, 1.0) and 1.0 (1.0, 1.0), and BNI-N scores [M (Q₁, Q₃)] of 1.0 (1.0, 1.0), 4.0 (3.0, 4.0), 3.0 (3.0, 4.0), 3.0 (2.0, 4.0) and 2.0 (2.0, 3.0), respectively. Compared with those at T₀, patients had lower BNI-P scores and higher BNI-N scores from T₁ to T₄ (all P<0.05). In all patients, group A, group B, and group C, the balloon volume was (0.65±0.15), (0.67±0.15), (0.59±0.15) and (0.67±0.17) cm³, respectively, with no statistically significant difference (P>0.05), while the Meckel's cave size was (0.42±0.12), (0.44±0.11), (0.32±0.07), and (0.57±0.11) cm³, with a statistically significant difference (P<0.001). The balloon volumes and Meckel's cave sizes were all linearly and positively correlated (r=0.852, 0.924, 0.937 and 0.969, all P<0.05). The compression coefficient in group A, B and C was (1.54±0.14), (1.84±0.18) and (1.18±0.10), respectively, with a statistically significant difference (P<0.001). There were no serious intraoperative complications such as death, diplopia, arteriovenous fistula, cerebrospinal fluid leak, and subarachnoid hemorrhage. Conclusions: Intraoperative balloon volume during PMC for trigeminal neuralgia is linearly and positively correlated with the volume of the patient's Meckel's cave. The compression coefficient varies among patients with different prognoses and the compression coefficient may be a factor affecting the patient's prognosis.

Carbonized Polymer Dots Assemble in Proton-Conducting Channels to Enhance the Conductivity and Selectivity Simultaneously for High-Performance Fuel Cells

Fabricating polymer electrolyte membranes (PEMs) simultaneously with high ion conductivity and selectivity has always been an ultimate goal in many membrane-integrated systems for energy conversion and storage. Constructing broader ion-conducting channels usually enables high-efficient ion conductivity while often bringing increased crossover of other ions or molecules simultaneously, resulting in decreased selectivity. Here, the ultra-small carbon dots (CDs) with the selective barriers are self-assembled within proton-conducting channels of PEMs through electrostatic interaction to enhance the proton conductivity and selectivity simultaneously. The functional CDs regulate the nanophase separation of PEMs and optimize the hydration proton network enabling higher-efficient proton transport. Meanwhile, the CDs within proton-conducting channels prevent fuel from permeating selectively due to their repelling and spatial hindrance against fuel molecules, resulting in highly enhanced selectivity. Benefiting from the improved conductivity and selectivity, the open-circuit voltage and maximum power density of the direct methanol fuel cell (DMFC) equipped with the hybrid membranes raised by 23% and 93%, respectively. This work brings new insight to optimize polymer membranes for efficient and selective transport of ions or small molecules, solving the trade-off of conductivity and selectivity.

Effect of the polar group content on the glass transition temperature of ROMP copolymers

Polar groups have long been recognized to greatly influence the glass transition temperature (T_g) of polymers, but understanding the underlying physical mechanism remains a challenge. Here, we study the glass formation of ring-opening metathesis polymerization (ROMP) copolymers containing polar groups by employing all-atom molecular dynamics simulations. We show that although the number of hydrogen bonds (N_HB) and the cohesive energy density increase linearly as the content of polar groups (f_pol) increases, the T_g of ROMP copolymers increases with the increase of f_pol in a nonlinear fashion, and tends to plateau for sufficiently high f_pol. Importantly, we find that the increase rate of Gibbs free energy for HB breaking gradually slows down with the increase of f_pol, indicating that the HB is gradually stabilized. Therefore, T_g is jointly determined by N_HB and the strength of HBs in the system, while the latter dominates. Although N_HB increases linearly with increasing f_pol, the HB strength increases slowly with increasing f_pol, which leads to a decreasing rate of increase in T_g.

[Efficacy of surgical treatment for pontine hemorrhage via infratemporal-prepetrosal approach]

Herein, the clinical data of 20 patients with pontine hemorrhage were retrospectively analyzed. All the patients underwent surgery via infratemporal-prepetrosal approach between January 2013 and June 2021 in the Department of Neurosurgery from the First Affiliated Hospital of Soochow University. There were 15 males and 5 females. The age ranged from 32 to 69 years, with an average age of 47.9 years. The course of disease was 3.5-16.0 h, with an average of 6.7 h. All the patients underwent surgery successfully. The hematomas of 17 patients were completely removed while the hematomas of the other 3 patients were partially removed. One patient died of multiple organ dysfunction syndrome during 30 days follow-up after surgery. The other patients were evaluated by Glasgow outcome scale (GOS), and the results showed that 1 patient was in Grade 5, 7 patients were in Grade 4, 6 patients were in Grade 3, 4 patients were in Grade 2, and 2 patients were in Grade 1. The surgery via infratemporal-prepetrosal approach is a safe, reasonable and feasible treatment for pontine hemorrhage. Especially for the patients who were younger than 50 years old, with high preoperative Glasgow Coma Scale (GCS) grade and surgical indications. This surgical technique can effectively reduce the mortality and improve the prognosis of patients with pontine hemorrhage. Moreover, patients should be operated within 6 hours after pontine hemorrhage as soon as possible.

Non-equilibrium Nanoassemblies Constructed by Confined Coordination on a Polymer Chain

Biological systems employ non-equilibrium self-assembly to create ordered nanoarchitectures with sophisticated functions. However, it is challenging to construct artificial non-equilibrium nanoassemblies due to lack of control over assembly dynamics and kinetics. Herein, we design a series of linear polymers with different side groups for further coordination-driven self-assembly based on shape-complementarity. Such a design introduces a main-chain confinement which effectively slows down the assembly process of side groups, thus allowing us to monitor the real-time evolution of lychee-like nanostructures. The function related to the non-equilibrium nature is further explored by performing photothermal conversion study. The ability to observe and capture non-equilibrium states in this supramolecular system will enhance our understanding of the thermodynamic and kinetic features as well as functions of living systems.

Platelet Aggregation Before Aspirin Initiation in Pediatric Patients With Congenital Heart Disease at High Risk of Thrombosis

Background

Aspirin following unfractionated heparin is the most common anticoagulation strategy for pediatric patients who experienced cardiac surgery at high risk of thrombosis. The platelet aggregation test is the golden method to evaluate the aspirin effect on platelet function. However, the platelet aggregation basal status before postoperative aspirin initiation and the related clinical influencing factors hasn't been investigated systemically in this population.

Methods

In a prospective cohort of 247 children, arachidonic acid-induced platelet aggregation (PAG-AA) was measured by means of light transmission aggregometry (LTA) before the first dose of aspirin after cardiac surgical procedure and the perioperative variables were also collected. Distribution of this population's PAG-AA basal status was described. Univariate and multivariate logistic regression analysis were performed to identify the main influencing factors of PAG-AA.

Results

The median time of aspirin administration was 2 (1–27) days after surgery and the corresponding median value of basal PAG-AA was 20.70% (1.28–86.49%), with 67.6% population under 55% and 47.8% population under 20%. Patients undergoing cardiopulmonary bypass (CPB) had a significantly lower basal PAG-AA than those without (30.63 ± 27.35 vs. 57.91 ± 27.58, p = 0.013). While patients whose test done within 3 days after CPB had a significantly lower PAG-AA than those out of 3 days (25.61 ± 25.59 vs. 48.59 ± 26.45, p = 0.001). Univariate analysis implied that the influencing factors of the basal PAG-AA including CPB use, test time point, cyanosis, and platelet count. Multivariate regression analysis indicated that only CPB use, test time point, and platelet count were the main independent influencing factors for the basal PAG-AA.

Conclusion

The majority of children have impaired basal platelet aggregometry responses before postoperative aspirin initiation. The main influencing factors are CPB use, test time point, and platelet count. To establish the platelet aggregometry baseline prior to commencement of aspirin therapy, testing should be performed 3 days later following the procedure when effect of CPB is basically over.

Nanoparticle cluster formation mechanisms elucidated via Markov state modeling: Attraction range effects, aggregation pathways, and counterintuitive transition rates

Nanoparticle clusters are promising candidates for developing functional materials. However, it is still a challenging task to fabricate them in a predictable and controllable way, which requires investigation of the possible mechanisms underlying cluster formation at the nanoscale. By constructing Markov state models (MSMs) at the microstate level, we find that for highly dispersed particles to form a highly aggregated cluster, there are multiple coexisting pathways, which correspond to direct aggregation, or pathways that need to pass through partially aggregated, intermediate states. Varying the range of attraction between nanoparticles is found to significantly affect pathways. As the attraction range becomes narrower, compared to direct aggregation, some pathways that need to pass through partially aggregated intermediate states become more competitive. In addition, from MSMs constructed at the macrostate level, the aggregation rate is found to be counterintuitively lower with a lower free-energy barrier, which is also discussed.

Physisorption of Poly(ethylene glycol) on Inorganic Nanoparticles

Poly(ethylene glycol) (PEG) is the most widely used polymer to decorate inorganic nanoparticles (NPs) by the "grafting-to" method for antifouling properties. PEG also shows diverse supramolecular interactions with nanoparticle surfaces and polar molecules, suggesting that the physisorption between PEG chains and NPs cannot be ignored in the "grafting-to" process. However, the effect of physisorption of PEG to NPs on the process of chemisorption has been rarely studied. Herein, we report that unfunctionalized PEG is physically adsorbed on various NPs by polyvalent supramolecular interactions, adopting "loop-and-train-tail" conformations. We investigated the effect of molecular weight of PEG and ligands of the NPs on the conformation of PEG chains by experimental methods and simulation. It is demonstrated that the physisorption of PEG on NPs can facilitate the chemisorption in the initial stages but delays it in the later stages during the "grafting-to" process. This work provides a deeper understanding of the conformation of physisorbed PEG on NPs and the relationship between physisorption and chemisorption.

[Effectiveness of influenza vaccination for school-age children in preventing school absenteeism in Shenzhen: an empirical study]

Objective: To assess the impact of vaccination at school and influenza vaccination rates among school-age children on school absenteeism in Shenzhen. Methods: The study subjects were primary school students in Shenzhen. School absenteeism panel database from December 2017 to June 2020 of 286 primary schools in Shenzhen was merged with vaccination rates and organizational patterns (i.e., vaccination at school vs. non-school) data of 9 districts in Shenzhen after influenza vaccination for children. The outcome was the number of school absenteeism. The treatment and control groups were distinguished by organizational patterns and district vaccination rates. Difference-in-Difference (DiD) Poisson regressions were used to analyze the effectiveness of vaccination at school and higher vaccination rates. Besides, a robustness test was performed on the regression results. Results: Poisson regression analysis and robustness test of regression results showed that vaccination at school and higher vaccination rates effectively reduced the risk of school absenteeism, with effectiveness against absenteeism of 32.6% (95%CI: 17.0%-45.3%, P<0.01) and 53.0% (95%CI: 42.1%-61.8%, P<0.01), respectively. Conclusion: A free influenza vaccination program for school-age children in Shenzhen and prioritizing school-based vaccination may be an effective measure to reduce the risk of school absenteeism.

Intercluster Exchange-Stabilized Novel Complex Colloidal χc Phase

Designing complex cluster crystals with a specific function using simple colloidal building blocks remains a challenge in materials science. Herein, we propose a conceptually new design strategy for constructing complex cluster crystals via hierarchical self-assembly of simple soft Janus colloids. A novel and previously unreported colloidal cluster-χ (χ_c) phase, which resembles the essential structural features of α-manganese but at a larger length scale, is obtained through molecular dynamics simulations. The formation of the χ_c phase undergoes a remarkable two-step self-assembly process, that is, the self-assembly of clusters with specific size dispersity from Janus colloids, followed by the highly ordered organization of these clusters. More importantly, the dynamic exchange of particles between these clusters plays a critical role in stabilizing the χ_c phase. Such a conceptual design framework based on intercluster exchange has the potential to effectively construct novel complex cluster crystals by hierarchical self-assembly of colloidal building blocks.

Supercooled melt structure and dynamics of single-chain nanoparticles: A computer simulation study

By using coarse-grained molecular dynamics simulations, we have investigated the structure and dynamics of supercooled single-chain cross-linked nanoparticle (SCNP) melts having a range of cross-linking degrees ϕ. We find a nearly linear increase in glass-transition temperature (T_g) with increasing ϕ. Correspondingly, we have also experimentally synthesized a series of polystyrene-based SCNPs and have found that the measured T_g estimated from differential scanning calorimetry is qualitatively consistent with the trend predicted by our simulation estimates. Experimentally, an increase in T_g as large as ΔT_g = 61 K for ϕ = 0.36 is found compared with their linear chain counterparts, indicating that the changes in dynamics with cross-links are quite appreciable. We attribute the increase in T_g to the enlarged effective hard-core volume and the corresponding reduction in the free volume of the polymer segments. Topological constraints evidently frustrate the local packing. In addition, the introduction of intra-molecular cross-linking bonds slows down the structural relaxation and simultaneously enhances the local coupling motion on the length scales within SCNPs. Consequently, a more pronounced dynamical heterogeneity (DH) is observed for larger ϕ, as quantified by measuring the dynamical correlation length through the four-point susceptibility parameter, χ₄. The increase in DH is directly related to the enhanced local cooperative motion derived from intra-molecular cross-linking bonds and structural heterogeneity derived from the cross-linking process. These results shed new light on the influence of intra-molecular topological constraints on the segmental dynamics of polymer melts.

Softness-Enhanced Self-Assembly of Pyrochlore- and Perovskite-like Colloidal Photonic Crystals from Triblock Janus Particles

It remains extremely challenging to build three-dimensional photonic crystals with complete photonic bandgaps by simple and experimentally realizable colloidal building blocks. Here, we demonstrate that particle softness can enhance both the self-assembly of pyrochlore- and perovskite-like lattice structures from simple deformable triblock Janus colloids and their photonic bandgap performances. Dynamics simulation results show that the region of stability of pyrochlore lattices can be greatly expanded by appropriately increasing softness, and the perovskite lattices are unexpectedly obtained at enough high softness. Photonic calculations show that the direct pyrochlore lattices formed from overlapping soft triblock Janus particles exhibit even larger photonic bandgaps than the ideal nonoverlapping pyrochlore lattice, and proper overlap arising from softness can also dramatically improve the photonic properties of the inverse pyrochlore and perovskite lattices. Our study offers a new and feasible self-assembly path toward three-dimensional photonic crystals with large and robust photonic bandgaps.

Solvent-Evaporation Induced and Mechanistic Entropy-Enthalpy-Balance Controlled Polymer Patch Formation on Nanoparticle Surfaces

The formation of polymer-patch nanoparticles (PNPs) involves a condensation process of grafted chains on a nanoparticle (NP) surface, which is conventionally achieved via a fine-tuning of the solvent quality. However, such a critical solvent condition differs dramatically between polymers, and the formation mechanism of different patchy structures remains under debate. In this study, we demonstrate by a combined simulation and experimental study that such a surface-patterning process can be easily achieved via a simple solvent evaporation process, which creates a natural nonsolvent condition and is, in principle, adaptable for all polymers. More importantly, we find that patchy structures are controlled by a delicate balance between enthalpic interaction and the entropy penalty of grafted chains. A small variation of cohesive energy density can lead to a dramatic change in patch structure. This work offers a robust yet easy approach for the fabrication of PNPs and provides new insights into polymer segregation on spherical surfaces.

Understanding of supramolecular emulsion interfacial polymerization in silico

The composition and structure of a membrane determine its functionality and practical application. We study the supramolecular polymeric membrane prepared by supramolecular emulsion interfacial polymerization (SEIP) on the oil-in-water droplet via the computer simulation method. The factors that may influence its structure and properties are investigated, such as the degree of polymerization and molecular weight distribution (MWD) of products in the polymeric membranes. We find that the SEIP can lead to a higher total degree of polymerization as compared to the supramolecular interfacial polymerization (SIP). However, the average chain length of products in the SEIP is lower than that of the SIP due to its obvious interface curvature. The stoichiometric ratio of reactants in two phases will affect the MWD of the products, which further affects the performance of the membranes in practical applications, such as drug release rate and permeability. Besides, the MWD of the product by SEIP obviously deviates from the Flory distribution as a consequence of the curvature of reaction interface. In addition, we obtain the MWD for the emulsions whose size distribution conforms to the Gaussian distribution so that the MWD may be predicted according to the corresponding emulsion size distribution. This study helps us to better understand the controlling factors that may affect the structure and properties of supramolecular polymeric membranes by SEIP.

Healable and Recyclable Elastomers with Record-High Mechanical Robustness, Unprecedented Crack Tolerance, and Superhigh Elastic Restorability

Spider silk is one of the most robust natural materials, which has extremely high strength in combination with great toughness and good elasticity. Inspired by spider silk but beyond it, a healable and recyclable supramolecular elastomer, possessing superhigh true stress at break (1.21 GPa) and ultrahigh toughness (390.2 MJ m^-3 ), which are, respectively, comparable to and ≈2.4 times higher than those of typical spider silk, is developed. The elastomer has the highest tensile strength (ultimate engineering stress, 75.6 MPa) ever recorded for polymeric elastomers, rendering it the strongest and toughest healable elastomer thus far. The hyper-robust elastomer exhibits superb crack tolerance with unprecedentedly high fracture energy (215.2 kJ m^-2 ) that even exceeds that of metals and alloys, and superhigh elastic restorability allowing dimensional recovery from elongation over 12 times. These extraordinary mechanical performances mainly originate from the meticulously engineered hydrogen-bonding segments, consisting of multiple acylsemicarbazide and urethane moieties linked with flexible alicyclic hexatomic spacers. Such hydrogen-bonding segments, incorporated between extensible polymer chains, aggregate to form geometrically confined hydrogen-bond arrays resembling those in spider silk. The hydrogen-bond arrays act as firm but reversible crosslinks and sacrificial bonds for enormous energy dissipation, conferring exceptional mechanical robustness, healability, and recyclability on the elastomer.

Block-copolymer-like self-assembly behavior of mobile-ligand grafted ultra-small nanoparticles

We use coarse-grained molecular dynamics simulations to study the self-assembly behavior of polyoxometalate (POM) nanoparticles (NPs) decorated with mobile polymer ligands under melt conditions. We demonstrate that due to the mobile nature of the grafted ligands on the NP surface, NPs have the ability to expose a part of their surfaces, leading to a block-copolymer-like self-assembly behavior. The exposed NP surface serves as one block and the grafted ligand polymers as another. This system has a strong ability to self-assemble into long-range ordered structures such as block copolymers due to large incompatibility between POM and ligand polymers, i.e., POM NPs can form lamellar, cylindrical, and spherical structures, which are consistent with previous experimental results. More importantly, these ordered structures are on the sub-10 nm scale, which is an important requirement for many applications. At low graft density, we find a new inverse-cylindrical structure formation where polymers form cylinders and POMs form a continuous network structure. A full self-assembly phase diagram is constructed which illustrates rules to manipulate the self-assembly structures of NPs decorated with mobile polymer ligands. We hope that these computational results will be useful for the new design of nanostructures with improved optical or electronic functions.

Mechanism of periodic field driven self-assembly process

Dissipative self-assembly, a ubiquitous type of self-assembly in biological systems, has attracted a lot of attention in recent years. Inspired by nature, dissipative self-assembly driven by periodic external fields is often adopted to obtain controlled out-of-equilibrium steady structures and materials in experiments. Although the phenomena in dissipative self-assembly have been discovered in the past few decades, fundamental methods to describe dynamical self-assembly processes and responsiveness are still lacking. Here, we develop a theoretical framework based on the equations of motion and Floquet theory to reveal the dynamic behavior changing with frequency in the periodic external field driven self-assembly. Using the dissipative particle dynamics simulation method, we then construct a block copolymer model that can self-assemble in dilute solution to confirm the conclusions from the theory. Our theoretical framework facilitates the understanding of dynamic behavior in a periodically driven process and provides the theoretical guidance for designing the dissipative conditions.

Polymerization-Induced Reassembly of Gemini Molecules toward Generating Porous Two-Dimensional Polymers

In situ polymerization of preorganized amphiphilic monomers on various substrates provides a flexible synthetic route to construct high-quality two-dimensional polymers (2DPs) with designed functionalities. However, the detailed polymerization kinetics of these monomers in 2D confinement and their impact on the structural features of 2DPs have not been efficiently explored. Here, using dissipative particle dynamics (DPD) simulations, we unveil the similarity of the polymerization kinetics of the amphiphilic Gemini molecules in both a 2D-confined space and solution and emphasize the key role of the initiator concentration in modifying the morphology of 2DPs. More interestingly, introducing a spacer group into the Gemini monomer facilitates the formation of porous 2DPs. The size and periodic arrangement of pores in these 2DPs could be directly controlled by the Gemini molecular geometries and polymerization kinetics. The insights based on our DPD simulations provide valuable guidelines for the rational design and synthesis of 2DPs from a wider range of amphiphilic molecules.

[Clinical characteristics and ketogenic diet therapy of glucose transporter type 1 deficiency syndrome in children: a multicenter clinical study]

Objective: To explore the clinical characteristics of pediatric glucose transporter type 1 deficiency syndrome (GLUT1 DS), evaluate the efficacy and safety of ketogenic diet therapy (KDT). Methods: Clinical data of 19 children with GLUT1 DS admitted to Children's Hospital of Fudan University, Tianjin Children's Hospital, Shenzhen Children's Hospital, Children's Hospital of Nanjing Medical University and Jiangxi Provincial Children's Hospital between 2015 and 2019 were collected retrospectively. The first onset symptom, main clinical manifestations, cerebrospinal fluid features and genetic testing results of patients were summarized, the efficacy and safety of ketogenic diet treatment were analyzed. Results: Among the 19 cases, 13 were males and 6 females. The age of onset was 11.0 (1.5-45.0) months,the age of diagnosis was 54.0 (2.8-132.0) months. Epilepsy was the first onset symptom of 13 cases. Different forms of tonic-clonic seizures were the most common types of epilepsy (7 cases with generalized tonic-clonic seizures, 5 cases with focal tonic or clonic seizures, 4 cases with generalized tonic seizures). Antiepileptic drugs were effective in 4 cases. Paroxysmal motor dysfunction was present in 12 cases and ataxia was the most common one. All patients had different degrees of psychomotor retardation. Among 17 patients received cerebrospinal fluid examination, cerebrospinal fluid (CSF) glucose level was lower than 2.2 mmol/L and CSF glucose/glycemic index was<0.45 in 16 cases, only 1 case presented normal CSF glucose level (2.3 mmol/L) and normal CSF glucose/glycemic index(0.47). SLC2A1 gene mutations were found in 16 patients, missense, frameshift and nonsense mutations were the common types with 5 cases, 5 cases and 3 cases respectively. All 19 patients were treated with ketogenic diet, which was effective in 18 cases in seizure control, 11 cases in dyskinesia improvement and 18 cases in cognitive function improvement. No serious side effects were reported in any stage of KDT. Conclusions: The diagnosis of GLUT1 DS is often late. It is necessary to improve the early recognition of the disease and perform CSF glucose detection and genetic testing as early as possible. The KDT is an effective and safe treatment for GLUT1 DS, but a small number of patients have not response to diet therapy.

Proper adsorptive confinement for efficient production of cyclic polymers: a dissipative particle dynamics study

Efficient production of cyclic polymers has been a hot topic in the past few decades. In this work, we found that an adsorptive porous template with an appropriate size has the capability to accelerate the ring closure of a linear polymer chain in a dilute solution with a higher yield. The restricted pore provides a confined space and the effect of its characteristics, such as pore size, shape and adsorption strength on cyclization time, is systematically studied by using dissipative particle dynamics simulations. As a prerequisite of cyclization in confinement, the entry process of linear precursors has been studied as well. Total production time is governed by a tradeoff between the size effect caused by decreasing the size of the pore and the adsorption of the pore. The strong size effect suppresses polymer entry but accelerates cyclization. The stronger adsorption promotes polymer entry but decelerates cyclization. According to our defined total production time, a small spherical confinement with strong adsorption results in a shorter total production time of cyclic polymers compared to that in free solution. If chain cyclization is permitted during its entering the confinement, the interplay between steric hindrance caused by pore size and adsorption provides an additional 'virtual' confinement at the boundary between confinement and free solution. In this case, an optimal cyclization time is observed with an appropriate adsorption strength under small confinement. Our results provide useful guidance for designing suitable porous templates for producing cyclic polymers with high efficiency.

The coarse-grained models of poly(ethylene oxide) and poly(propylene oxide) homopolymers and poloxamers in big multipole water (BMW) and MARTINI frameworks

Polyethylene oxide (PEO) and poly(propylene oxide) (PPO), especially their tri-block copolymers PEO-PPO-PEO (poloxamers), have a broad range of applications in biotechnology and medical science. Understanding their specific interactions with biomembranes is the key to unveil the unique features of poloxamers either as membrane-healing or membrane pore-forming agents. Based on the coarse-graining convention of the MARTINI force field and the big multipole water (BMW) model, which has a three charged site topology and can reproduce the correct dipole moment of four-water clusters, we generated coarse-grained (CG) models with analytical and numerical potentials for PEO and PPO homopolymers and poloxamers in dilute solution. The effective bonded interaction potentials between CG beads were determined from the probability distributions of bond lengths, angles and dihedrals that are determined from atomistic simulations. The nonbonded interaction parameters were fine-tuned to reproduce the conformational properties of atomistic PEO and PPO homopolymers and poloxamers via extensive CG simulations of PEO and PPO homopolymers and poloxamers in a BMW water environment. The reported CG models provide a promising framework for a comprehensive understanding of the microstructural, conformational, and dynamic properties of poloxamers and their delicate interactions with other species in an explicit water environment.

Microstructural and Dynamical Heterogeneities in Ionic Liquids

Ionic liquids (ILs) are a special category of molten salts solely composed of ions with varied molecular symmetry and charge delocalization. The versatility in combining varied cation-anion moieties and in functionalizing ions with different atoms and molecular groups contributes to their peculiar interactions ranging from weak isotropic associations to strong, specific, and anisotropic forces. A delicate interplay among intra- and intermolecular interactions facilitates the formation of heterogeneous microstructures and liquid morphologies, which further contributes to their striking dynamical properties. Microstructural and dynamical heterogeneities of ILs lead to their multifaceted properties described by an inherent designer feature, which makes ILs important candidates for novel solvents, electrolytes, and functional materials in academia and industrial applications. Due to a massive number of combinations of ion pairs with ion species having distinct molecular structures and IL mixtures containing varied molecular solvents, a comprehensive understanding of their hierarchical structural and dynamical quantities is of great significance for a rational selection of ILs with appropriate properties and thereafter advancing their macroscopic functionalities in applications. In this review, we comprehensively trace recent advances in understanding delicate interplay of strong and weak interactions that underpin their complex phase behaviors with a particular emphasis on understanding heterogeneous microstructures and dynamics of ILs in bulk liquids, in mixtures with cosolvents, and in interfacial regions.

Spontaneous Formation of Moiré Patterns through Self-Assembly of Janus Nanoparticles

Two periodic two-dimensional lattices overlap with each other with a twisted angle can result in moiré patterns (MPs). In this in silico study, we show that by using amphiphilic Janus nanoparticles (JNPs) as a building block, the MPs of JNPs emerge spontaneously via direct self-assembly in dilute solution without additional complicated operation. The formation of MPs is attributed to the hydrophobicity of the nanoparticles (and the so-induced "force strings" at the membrane rim) together with suitable grafted hydrophilic and hydrophobic chain lengths. The mass production of MPs with controlled size can be fulfilled by adding stabilizers that effectively reduce the line tension at the rim of membranes with MPs.

The interfacial structure and dynamics in a polymer nanocomposite containing small attractive nanoparticles: a full atomistic molecular dynamics simulation study

We study the interfacial structure and dynamics of a polymer nanocomposite (PNC) composed of octaaminophenyl polyhedral oligomeric silsesquioxane (OAPS) and poly(2-vinylpyridine) (P2VP) by performing full atomistic molecular dynamics simulations. There are eight aminophenyl groups grafted on the surface of the OAPS particle and the particle has a size comparable to the Kuhn segment of P2VP. These aminophenyl groups can form hydrogen bonds (HBs) with pyridine rings from surrounding P2VP chains. We found that OAPS can form ∼2 HBs on average with surrounding polymer chains. The effect of the HBs is investigated in detail by either switching on or off these HBs in our simulation. By analyzing the interfacial static packing structure and dynamic properties, we demonstrate that the system has an ∼1 nm interface width, similar to the OAPS particle size. We also found that HBs can prevent the further penetration of polymers into the inner zone (grafting layer) of the OAPS, and therefore keep the P2VP chains in the outer layer (>1 nm), remaining bulk-like, which is well consistent with experimental results. In addition, we found that NP diffusion is coupled to the absorbed polymer chains, which also dramatically slows down the diffusion of polymer segments in return. The core-shell model in which the NP and absorbed polymers diffuse as a single object is validated here at the full atomistic level. These results provide atomistic insights into the unique structure and dynamics in the small attractive NP-polymer interfacial region. We hope these results will be helpful for the understanding of peculiar phenomena in attractive polymer nanocomposites containing small NPs.

Highly efficient, reversible iodine capture and exceptional uptake of amines in viologen-based porous organic polymers

A viologen-based porous organic polymer, POP-V-VI, was designed and synthesized by a facile nucleophilic substitution between cyanuric chloride and 1,2-bis(4-pyridinium) ethylene. Together with the reported POP-V-BPY with a similar structure, these viologen-based porous organic polymers bear high charge density, phenyl ring and nitrogenous affinity sites, which endow them with excellent iodine vapor uptake capacity (4860 mg g-1 for POP-V-VI and 4200 mg g-1 for POP-V-BPY) and remarkably high adsorption capacity for pyridine (4470 mg g-1 for POP-V-VI and 8880 mg g-1 for POP-V-BPY) and other aliphatic amines. POP-V-VI and POP-V-BPY could be efficiently recycled and reused three times without significant loss of iodine vapor uptake. All these results demonstrate that POP-V-VI and POP-V-BPY are promising adsorbents for practical applications in portable devices such as gas masks.

Synthesis of Polymer Single-Chain Nanoparticle with High Compactness in Cosolvent Condition: A Computer Simulation Study

Polymeric single-chain nanoparticles (SCNPs) are soft nano-objects synthesized by intramolecular crosslinking of isolated single polymer chains. Syntheses of such SCNPs usually need to be performed in a dilute solution. In such a condition, the bonding probability of the two active crosslinking units at a short contour distance along the chain backbone is much higher than those which are far away from each other. Such a reaction condition often results in local spheroidization and, therefore, the formation of loosely packed structures. How to inhibit the local spheroidization and improve the compactness of SCNPs is thus a major challenge for the syntheses of SCNPs. In this study, computer simulations are performed and the fact that a precollapse of the polymer chain conformation in a cosolvent condition can largely improve the probability of the crosslinking reactions at large contour distances is demonstrated, favoring the formations of closely packed globular structures. As a result, the formed SCNPs can be more spherical and have higher compactness than those fabricated in ultradilute good solvent solution in a conventional way. It is believed this simulation work can provide a insight into the effective syntheses of SCNPs with spherical conformations and high compactness.

Simulation Study of Process-Controlled Supramolecular Block Copolymer Phase Separation with Reversible Reaction Algorithm

A supramolecular diblock copolymer formed by reversible bonds between the two blocks shows a rich microphase separation behavior and has great application potential in stimuli-responsive materials. We propose a novel method to describe supramolecular reactions in dissipative particle dynamics, which includes a reversible reaction to accurately reproduce the strength, saturation, and dynamic properties of the reversible bonds in the simulations. The thermodynamic properties and dynamic processes of the supramolecular diblock copolymer melts in both equilibrium and non-equilibrium states were studied using this method. The simulation results show that the method can faithfully characterize phase behaviors and dynamic properties of supramolecular diblock copolymer melts, especially in a non-equilibrium state, which provides a novel tool to unveil self-assembly mechanism and describe the properties of supramolecular block copolymers.

Kinetics-controlled design principles for two-dimensional open lattices using atom-mimicking patchy particles

The design and discovery of new two-dimensional materials with desired structures and properties are always one of the most fundamental goals in materials science. Here we present an atom-mimicking design concept to achieve direct self-assembly of two-dimensional low-coordinated open lattices using three-dimensional patchy particle systems. Besides honeycomb lattices, a new type of two-dimensional square-octagon lattice is obtained through rational design of the patch configuration of soft three-patch particles. However, unexpectedly the building blocks with thermodynamically favoured patch configuration cannot form square-octagon lattices in our simulations. We further reveal the kinetic mechanisms controlling the formation of the honeycomb and square-octagon lattices. The results indicate that the kinetically favoured intermediates play a critical role in determining the structure of obtained open lattices. This kinetics-controlled design principle provides a particularly effective and extendable framework to construct other novel open lattice structures.

Microscopic characteristics of Janus nanoparticles prepared via a grafting-from reaction at the immiscible liquid interface

The dynamic process of synthesizing Janus nanoparticles (JNPs) at a water/oil two-phase interface using a grafting-from reaction is investigated via dissipative particle dynamics simulations. We find that the interfacial tension, the initial monomer concentration, and the reaction probability can greatly influence the microscopic characteristics of JNP structure. It is difficult to synthesize a symmetric JNP with an equal volume ratio between hydrophilic and hydrophobic parts by grafting-from methods unless the physical chemical conditions in the two phases are strictly symmetric, and there is always a disordered domain on the JNP at a two immiscible solvents interface. Interestingly, for certain routes for synthesizing JNPs with a grafting-from method, the higher interfacial tension between the water and oil phases may enhance the degree of disorder of the grafted chains. The asymmetric initial monomer concentration in solution and the reaction probability can be used to control the syntheses of asymmetric JNPs.

An unexpected N-dependence in the viscosity reduction in all-polymer nanocomposite

Adding small nanoparticles (NPs) into polymer melt can lead to a non-Einstein-like decrease in viscosity. However, the underlying mechanism remains a long-standing unsolved puzzle. Here, for an all-polymer nanocomposite formed by linear polystyrene (PS) chains and PS single-chain nanoparticles (SCNPs), we perform large-scale molecular dynamics simulations and experimental rheology measurements. We show that with a fixed (small) loading of the SCNP, viscosity reduction (VR) effect can be largely amplified with an increase in matrix chain length \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$N$$\end{document}N, and that the system with longer polymer chains will have a larger VR. We demonstrate that such \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$N$$\end{document}N-dependent VR can be attributed to the friction reduction experienced by polymer segment blobs which have similar size and interact directly with these SCNPs. A theoretical model is proposed based on the tube model. We demonstrate that it can well describe the friction reduction experienced by melt polymers and the VR effect in these composite systems.

Addition of small nanoparticles into polymer melt can lead to decrease in viscosity but the underlying mechanism for such viscosity reduction remains unclear. Here, the authors investigate the reduction in viscosity by large-scale molecular dynamics simulation and experimental rheology measurements for an all-polymer nanocomposite formed by linear polystyrene chains and PS single-chain nanoparticle.

[Study on the oral mucosal diseases in patients with cerebrovascular diseases]

Objective: To investigate the prevalence of oral mucosal diseases (OMD) in patients with cerebrovascular disease. Methods: A total of 182 patients with cerebrovascular disease and 166 controls were examined for OMD to compare the differences of prevalence rates. Results: The prevalence of OMD in patients with cerebrovascular disease appeared higher than that in the control group. Oral candidiasis was most commonly seen (11.1%, 20/182), followed by fissured tongue (5.0%, 9/182), traumatic ulcer (2.8%, 5/182), herpes labialis (2.2%, 4/182), recurrent oral ulcer (1.6%, 3/182), chronic cheilitis (1.6%, 3/182) and oral leukokeratosis (1.6%, 3/182). Conclusion: Patients with cerebrovascular diseases were susceptible to OMDs, especially to oral candidiasis that called for more attention.

Gold Nanotetrapods with Unique Topological Structure and Ultranarrow Plasmonic Band as Multifunctional Therapeutic Agents

Owing to their excellent surface plasmonic properties, Au nanobranches have drawn increasing attention in various bioapplications, such as contrast agents for photoacoustic imaging, nanomedicines for photothermal therapy, and carriers for drug delivery. The monodispersity and plasmonic bandwidth of Au nanobranches are of great importance for the efficacy of those bioapplications. However, it is still a challenge to accurately synthesize size- and shape-controlled Au nanobranches. Here we report a facile seed-mediated growth method to synthesize monodisperse Au nanotetrapods (NTPs) with tunable and ultranarrow plasmonic bands. The NTPs have a novel D_2d symmetry with four arms elongated in four ⟨110⟩ directions. The growth mechanism of NTPs relies on the delicate kinetic control of deposition and diffusion rates of adatoms. Upon laser irradiation, the PEGylated NTPs possess remarkable photothermal conversion efficiencies and photoacoustic imaging properties. The NTPs can be applied as a multifunctional theranostic agent for both photoacoustic imaging and image-guided photothermal therapy.