Oxidation behavior and atomic structural transition of size-selected coalescence-resistant tantalum nanoclusters

Herein a series of size-selected TaN (N=147, 309, 561, 923, 1415, 2057, 6525, 10000, 20000) clusters are generated using a gas-phase condensation cluster beam source equipped with a lateral time-of-flight (TOF) mass-selector. Aberration-corrected scanning transmission electron microscopy (AC-STEM) imaging reveals good thermal stability of TaN clusters in this study. The oxidation-induced amorphization is observed from AC-STEM imaging and further demonstrated through X-ray photoelectron spectroscopy (XPS) and energy-dispersive spectroscopy (EDS). The oxidized Ta predominantly exists in the +5 oxidation state and the maximum spontaneous oxidation depth of Ta cluster is observed to be 5 nm under prolonged atmosphere exposure. Furthermore, the size-dependent sintering and crystallization process of oxidized TaN clusters is observed with in-situ heating technique, and eventually, ordered structures are restored. As temperature reaches 1300 °C, a fraction of oxidized Ta309 clusters exhibit decahedral and icosahedral structures, but the five-fold symmetry structures are absent in larger clusters, instead, these clusters exhibit ordered structures resembling those of the crystalline Ta2O5 films. Notably, the sintering and crystallization process occurs at temperatures significantly lower than the melting point of Ta and Ta2O5, and the ordered structures resulting from annealing remain well-preserved after six months of exposure to ambient condition. .

Observation of giant non-reciprocal charge transport from quantum Hall states in a topological insulator

Symmetry breaking in quantum materials is of great importance and can lead to non-reciprocal charge transport. Topological insulators provide a unique platform to study non-reciprocal charge transport due to their surface states, especially quantum Hall states under an external magnetic field. Here we report the observation of non-reciprocal charge transport mediated by quantum Hall states in devices composed of the intrinsic topological insulator Sn-Bi1.1Sb0.9Te2S, which is attributed to asymmetric scattering between quantum Hall states and Dirac surface states. A giant non-reciprocal coefficient of up to 2.26 × 105 A-1 is found. Our work not only reveals the properties of non-reciprocal charge transport of quantum Hall states in topological insulators but also paves the way for future electronic devices.

Enhanced magnetic anisotropy of iridium dimers on antisite defects of two-dimensional transition-metal dichalcogenides

The combination of transition-metal (TM) elements with two-dimensional (2D) transition-metal dichalcogenides (TMDs) provides an effective route to realizing a 2D controllable magnetic order, leading to significant applications in multifunctional nanospintronics. However, in most TM atoms@TMDs nanostructures, it is challenging for the magnetic anisotropy energy (MAE) to exceed 30 meV when affected by the crystal field. Hence, the stronger magnetic anisotropy of TMDs has yet to be developed. Here, utilizing first-principle calculations based on density functional theory (DFT), a feasible method to enhance the MAEs of TMDs via configurating iridium dimers (Ir2) on 2D traditional and Janus TMDs with antisite defects is reported. Calculations revealed that 28 of the 54 configurations considered possessed structure-dependent MAEs of >60 meV per Ir2 in the out-of-plane direction, suggesting the potential for applications at room temperature. We also showed the ability to tune the MAE further massively by applying a biaxial strain as well as the surface asymmetric polarization reversal of Janus-type substrates. This approach led to changes to >80 meV per Ir2. This work provides a novel strategy to achieve tunable large magnetic anisotropy in 2D TMDs. It also extends the functionality of antisite-defective TMDs, thereby providing theoretical support for the development of magnetic nanodevices.

Light-induced giant enhancement of nonreciprocal transport at KTaO3-based interfaces

Nonlinear transport is a unique functionality of noncentrosymmetric systems, which reflects profound physics, such as spin-orbit interaction, superconductivity and band geometry. However, it remains highly challenging to enhance the nonreciprocal transport for promising rectification devices. Here, we observe a light-induced giant enhancement of nonreciprocal transport at the superconducting and epitaxial CaZrO3/KTaO3 (111) interfaces. The nonreciprocal transport coefficient undergoes a giant increase with three orders of magnitude up to 105 A-1 T-1. Furthermore, a strong Rashba spin-orbit coupling effective field of 14.7 T is achieved with abundant high-mobility photocarriers under ultraviolet illumination, which accounts for the giant enhancement of nonreciprocal transport coefficient. Our first-principles calculations further disclose the stronger Rashba spin-orbit coupling strength and the longer relaxation time in the photocarrier excitation process, bridging the light-property quantitative relationship. Our work provides an alternative pathway to boost nonreciprocal transport in noncentrosymmetric systems and facilitates the promising applications in opto-rectification devices and spin-orbitronic devices.

Investigation of the accuracy of dynamic condylar position: A model study

OBJECTIVES

To evaluate dynamic condylar positions by integrating mandibular movement recording data and cone-beam computed tomography (CBCT) and to investigate its accuracy via dynamic model experiments.

METHODS

A polyvinyl chloride skull model was utilized. A robot arm was used to operate the mandible to perform mouth opening, closing, protrusion, and lateral movements. A recording device, worn on the skull, was used to record the dynamic process and an optical position tracking (OPT) system was used to simultaneously trace the movements. A self-developed software module was used to evaluate the dynamic condylar position by integrating the dynamic tracing data and a virtual skull model derived from CBCT images. Errors were defined as differences between the dynamic coordinates of six landmarks around the condylar area derived from the software module (test) and OPT system (gold standard).

RESULTS

The condylar position errors were 0.76 ± 0.31, 0.55 ± 0.15, and 0.68 ± 0.23 mm for mouth opening, bilateral, and protrusion movements, respectively. Furthermore, the errors for small, moderate, and large mouth opening movements were 0.62 ± 0.19, 0.69 ± 0.29, and 0.94 ± 0.31 mm, respectively. The errors for all movements, except for large mouth opening, were significantly less than 1 mm (P < 0.05). The error was not different from 1 mm in the large mouth opening movement (P > 0.05).

CONCLUSIONS

Our developed method of achieving dynamic condylar position by integrating mandibular movement recording data and CBCT images is clinically reliable.

CLINICAL SIGNIFICANCE

This study proved the reliability of evaluating dynamic condylar position using a commercial dynamic recording instrument and CBCT images.

Longitudinal profiling identifies co-occurring BRCA1/2 reversions, TP53BP1, RIF1 and PAXIP1 mutations in PARP inhibitor-resistant advanced breast cancer

BACKGROUND

Resistance to therapies that target homologous recombination deficiency (HRD) in breast cancer limits their overall effectiveness. Multiple, preclinically validated, mechanisms of resistance have been proposed, but their existence and relative frequency in clinical disease are unclear, as is how to target resistance.

PATIENTS AND METHODS

Longitudinal mutation and methylation profiling of circulating tumour (ct)DNA was carried out in 47 patients with metastatic BRCA1-, BRCA2- or PALB2-mutant breast cancer treated with HRD-targeted therapy who developed progressive disease-18 patients had primary resistance and 29 exhibited response followed by resistance. ctDNA isolated at multiple time points in the patient treatment course (before, on-treatment and at progression) was sequenced using a novel >750-gene intron/exon targeted sequencing panel. Where available, matched tumour biopsies were whole exome and RNA sequenced and also used to assess nuclear RAD51.

RESULTS

BRCA1/2 reversion mutations were present in 60% of patients and were the most prevalent form of resistance. In 10 cases, reversions were detected in ctDNA before clinical progression. Two new reversion-based mechanisms were identified: (i) intragenic BRCA1/2 deletions with intronic breakpoints; and (ii) intragenic BRCA1/2 secondary mutations that formed novel splice acceptor sites, the latter being confirmed by in vitro minigene reporter assays. When seen before commencing subsequent treatment, reversions were associated with significantly shorter time to progression. Tumours with reversions retained HRD mutational signatures but had functional homologous recombination based on RAD51 status. Although less frequent than reversions, nonreversion mechanisms [loss-of-function (LoF) mutations in TP53BP1, RIF1 or PAXIP1] were evident in patients with acquired resistance and occasionally coexisted with reversions, challenging the notion that singular resistance mechanisms emerge in each patient.

CONCLUSIONS

These observations map the prevalence of candidate drivers of resistance across time in a clinical setting, information with implications for clinical management and trial design in HRD breast cancers.

Defect-induced helicity dependent terahertz emission in Dirac semimetal PtTe2 thin films

Nonlinear transport enabled by symmetry breaking in quantum materials has aroused considerable interest in condensed matter physics and interdisciplinary electronics. However, achieving a nonlinear optical response in centrosymmetric Dirac semimetals via defect engineering has remained a challenge. Here, we observe the helicity dependent terahertz emission in Dirac semimetal PtTe2 thin films via the circular photogalvanic effect under normal incidence. This is activated by a controllable out-of-plane Te-vacancy defect gradient, which we unambiguously evidence with electron ptychography. The defect gradient lowers the symmetry, which not only induces the band spin splitting but also generates the giant Berry curvature dipole responsible for the circular photogalvanic effect. We demonstrate that the THz emission can be manipulated by the Te-vacancy defect concentration. Furthermore, the temperature evolution of the THz emission features a minimum in the THz amplitude due to carrier compensation. Our work provides a universal strategy for symmetry breaking in centrosymmetric Dirac materials for efficient nonlinear transport.

Magnetotransport spectroscopy of electroburnt graphene nanojunctions

We have reported the precise methodology for fabricating graphene quantum dots through electroburning and performed measurements on the Coulomb blockade and oscillation phenomena. The diameters of graphene quantum dots can be estimated to range from several to tens of nanometers, utilizing the disk capacitance model and the two-dimensional quantum well model. By subjecting the quantum dots to a vertical magnetic field, an obvious alteration in conductance can be detected at the point of resonance tunneling. This observed phenomenon can be attributed to the modification in the density of states of Landau levels within the graphene leads. Moreover, by manipulating the gate voltage, it is possible to regulate the Fermi level of the lead, resulting in distinct magnetoresistance of different electron states. The presence of this lead effect may potentially disrupt the magnetic response analysis of graphene-based single-molecule transistors, necessitating a comprehensive theoretical examination to mitigate such interference.

Electrically controlled nonvolatile switching of single-atom magnetism in a Dy@C84 single-molecule transistor

Single-atom magnetism switching is a key technique towards the ultimate data storage density of computer hard disks and has been conceptually realized by leveraging the spin bistability of a magnetic atom under a scanning tunnelling microscope. However, it has rarely been applied to solid-state transistors, an advancement that would be highly desirable for enabling various applications. Here, we demonstrate realization of the electrically controlled Zeeman effect in Dy@C84 single-molecule transistors, thus revealing a transition in the magnetic moment from 3.8μ B to 5.1μ B for the ground-state GN at an electric field strength of 3 - 10 MV/cm. The consequent magnetoresistance significantly increases from 600% to 1100% at the resonant tunneling point. Density functional theory calculations further corroborate our realization of nonvolatile switching of single-atom magnetism, and the switching stability emanates from an energy barrier of 92 meV for atomic relaxation. These results highlight the potential of using endohedral metallofullerenes for high-temperature, high-stability, high-speed, and compact single-atom magnetic data storage.

Treatment of auricular pseudocysts using enhanced negative drainage: a prospective study of 21 cases

OBJECTIVE

Auricular pseudocysts are rare, painless, benign intracartilaginous cysts of the auricle that are not lined by epithelium and have no known aetiology.

METHOD

This was a prospective study conducted in an ENT department from January 2020 to June 2022. In 21 patients, complete aspiration of the pseudocyst with enhanced negative drainage was performed. They were followed for a minimum of six months.

RESULTS

All patients completely responded to the negative drainage treatment. No cases of recurrence or obvious deformities were observed.

CONCLUSION

Aspiration with intensified negative drainage was associated with a positive response in patients with auricular pseudocysts. Complete resolution of the swelling can be achieved without any serious complications. Thus, it appears to be a simple and effective method for managing the condition.

Influence of ligands on the optical properties of rod-shaped Au25 nanoclusters

In this study, we successfully synthesized rod-shaped [Au25(PPh3)10(S-Adm)5Cl2]2+ nanoclusters using kinetic controls. The complete molecular structure was determined by single-crystal X-ray crystallography and electrospray ionization mass spectrometry. In comparison with the previously reported [Au25(PPh3)10(PET)5Cl2]2+ clusters, both nanoclusters have an icosahedral composition of Au13 linked by Au atoms that share a vertex, but [Au25(PPh3)10(S-Adm)5Cl2]2+ clusters appear elongated due to the rigidity of adamantane. We conducted ultraviolet-visible spectrophotometry (UV-vis) measurements of [Au25(PPh3)10(PET)5Cl2]2+ and [Au25(PPh3)10(S-Adm)5Cl2]2+ in dichloromethane solvent to elucidate the modulation of the cluster properties of different ligands. The lowest energy absorption peak of [Au25(PPh3)10(S-Adm)5Cl2]2+ shifted to lower energies compared to the [Au25(PPh3)10(PET)5Cl2]2+ clusters in UV-vis measurements. Temperature-dependent absorption measurements revealed that [Au25(PPh3)10(S-Adm)5Cl2]2+ clusters were less affected by temperature compared to [Au25(PPh3)10(PET)5Cl2]2+. This result is attributed to the exciton phonon coupling of [Au25(PPh3)10(S-Adm)5Cl2]2+ clusters being weaker than [Au25(PPh3)10(PET)5Cl2]2+ clusters. Furthermore, the absorption spectra of [Au25(PPh3)10(PET)5Cl2]2+ and [Au25(PPh3)10(S-Adm)5Cl2]2+ clusters were measured using different types of solutions, and it was found that the lowest energy absorption peaks of [Au25(PPh3)10(S-Adm)5Cl2]2+ were shifted and affected by the solution at room temperature, which suggested that the [Au25(PPh3)10(S-Adm)5Cl2]2+ clusters with solution hydrogen bonds also interacted strongly at room temperature. Theoretical calculations show that changes in ligands affect the differences in the molecular orbitals and structures of the clusters, which cause changes in the optical properties.

Broadband and Spectrally Selective Photothermal Conversion through Nanocluster Assembly of Disordered Plasmonic Metasurfaces

Plasmonic metasurfaces have been realized for efficient light absorption, thereby leading to photothermal conversion through nonradiative decay of plasmonic modes. However, current plasmonic metasurfaces suffer from inaccessible spectral ranges, costly and time-consuming nanolithographic top-down techniques for fabrication, and difficulty of scale-up. Here, we demonstrate a new type of disordered metasurface created by densely packing plasmonic nanoclusters of ultrasmall size on a planar optical cavity. The system either operates as a broadband absorber or offers a reconfigurable absorption band right across the visible region, resulting in continuous wavelength-tunable photothermal conversion. We further present a method to measure the temperature of plasmonic metasurfaces via surface-enhanced Raman spectroscopy (SERS), by incorporating single-walled carbon nanotubes (SWCNTs) as an SERS probe within the metasurfaces. Our disordered plasmonic system, generated by a bottom-up process, offers excellent performance and compatibility with efficient photothermal conversion. Moreover, it also provides a novel platform for various hot-electron and energy-harvesting functionalities.

Tunable optical topological transitions of plasmon polaritons in WTe2 van der Waals films

Naturally existing in-plane hyperbolic polaritons and the associated optical topological transitions, which avoid the nano-structuring to achieve hyperbolicity, can outperform their counterparts in artificial metasurfaces. Such plasmon polaritons are rare, but experimentally revealed recently in WTe2 van der Waals thin films. Different from phonon polaritons, hyperbolic plasmon polaritons originate from the interplay of free carrier Drude response and interband transitions, which promise good intrinsic tunability. However, tunable in-plane hyperbolic plasmon polariton and its optical topological transition of the isofrequency contours to the elliptic topology in a natural material have not been realized. Here we demonstrate the tuning of the optical topological transition through Mo doping and temperature. The optical topological transition energy is tuned over a wide range, with frequencies ranging from 429 cm-1 (23.3 microns) for pure WTe2 to 270 cm-1 (37.0 microns) at the 50% Mo-doping level at 10 K. Moreover, the temperature-induced blueshift of the optical topological transition energy is also revealed, enabling active and reversible tuning. Surprisingly, the localized surface plasmon resonance in skew ribbons shows unusual polarization dependence, accurately manifesting its topology, which renders a reliable means to track the topology with far-field techniques. Our results open an avenue for reconfigurable photonic devices capable of plasmon polariton steering, such as canaling, focusing, and routing, and pave the way for low-symmetry plasmonic nanophotonics based on anisotropic natural materials.

Slice Visualization for Imaging Nanocluster Transformations

Metal nanoclusters have served as an emerging class of modular nanomaterials. Several efficient strategies have been proposed for transforming cluster precursors into new nanoclusters with customized structures and enhanced performance. However, such nanocluster transformations have still been in a "blind box" state, meaning that the existing intermediates were hard to track with atomic precision. Herein, we present a "slice visualization" approach for in-depth imaging of the nanocluster transformation from Au₁Ag₂₄(SR)₁₈ to Au₁Ag₃₀(SR)₂₀. With this approach, two cluster intermediates, namely, Au₁Ag₂₆(SR)₁₉ and Au₁Ag₂₈(SR)₂₀, were monitored with atomic precision. The four nanoclusters constituted a correlated Au₁Ag_24+2n (n = 0, 1, 2, and 3) cluster series with comparable structural features─the same Au₁Ag₁₂ icosahedral kernel but evolutionary peripheral motif structures. The mechanism of nanocluster structure growth was mapped in detail─insertion of Ag₂(SR)₁ or Ag-induced assembly of surface subunits. The presented "slice visualization" approach not only contributes an ideal cluster platform for in-depth investigations of structure-property correlations but also hopefully acts as a powerful means for obtaining clear information on nanocluster structure evolution.

Enhanced Superconductivity and Upper Critical Field in Ta-Doped Weyl Semimetal Td -MoTe2

2D transition metal dichalcogenides are promising platforms for next-generation electronics and spintronics. The layered Weyl semimetal (W,Mo)Te₂ series features structural phase transition, nonsaturated magnetoresistance, superconductivity, and exotic topological physics. However, the superconducting critical temperature of the bulk (W,Mo)Te₂ remains ultralow without applying a high pressure. Here, the significantly enhanced superconductivity is observed with a transition temperature as large as about 7.5 K in bulk Mo_{1- x} Ta_x Te₂ single crystals upon Ta doping (0 ≤ x ≤ 0.22), which is attributed to an enrichment of density of states at the Fermi level. In addition, an enhanced perpendicular upper critical field of 14.5 T exceeding the Pauli limit is also observed in T_d -phase Mo_{1- x} Ta_x Te₂ (x = 0.08), indicating the possible emergence of unconventional mixed singlet-triplet superconductivity owing to the inversion symmetry breaking. This work provides a new pathway for exploring the exotic superconductivity and topological physics in transition metal dichalcogenides.

Processing Optimization of Shear Thickening Fluid Assisted Micro-Ultrasonic Machining Method for Hemispherical Mold Based on Integrated CatBoost-GA Model

Micro-electro-mechanical systems (MEMS) hemispherical resonant gyroscopes are used in a wide range of applications in defense technology, electronics, aerospace, etc. The surface roughness of the silicon micro-hemisphere concave molds (CMs) inside the MEMS hemispherical resonant gyroscope is the main factor affecting the performance of the gyroscope. Therefore, a new method for reducing the surface roughness of the micro-CM needs to be developed. Micro-ultrasonic machining (MUM) has proven to be an excellent method for machining micro-CMs; shear thickening fluids (STFs) have also been used in the ultra-precision polishing field due to their perfect processing performance. Ultimately, an STF-MUM polishing method that combines STF with MUM is proposed to improve the surface roughness of the micro-CM. In order to achieve the excellent processing performance of the new technology, a Categorical Boosting (CatBoost)-genetic algorithm (GA) optimization model was developed to optimize the processing parameters. The results of optimizing the processing parameters via the CatBoost-GA model were verified by five groups of independent repeated experiments. The maximum absolute error of CatBoost-GA is 7.21%, the average absolute error is 4.69%, and the minimum surface roughness is reduced by 28.72% compared to the minimum value of the experimental results without optimization.

[The role of CD4+ CD25+ Treg in the mechanism of autoimmune auditory neuropathy in SD rats]

Objective: To investigate the role of CD4⁺CD25⁺regulatory cell (CD4⁺CD25⁺Treg) in auditory neuropathy (AN) using a rat model of autoimmune auditory neuropathy. Methods: The SD rats were immunized with P0 protein emulsified in complete Freunds adjuvant for 8 weeks. The number of CD4⁺CD25⁺Treg in peripheral blood and cochlea and the expression of Foxp3 gene in cochlea were detected respectively 2, 4, 6 and 8 weeks after the immunization with P0 protein in rats. Then CD4⁺CD25⁺Treg were transferred intravenously to the AN rats at 2, 4, 6 and 8 weeks of the immunization, respectively. The change of auditory brainstem response (ABR) and distortion product otoacoustic emission (DPOAE) were detected, and the morphological changes in the inner ear were investigated. Results: The number of CD4⁺CD25⁺Treg in the peripheral blood of AN rats decreased gradually after 2, 4, 6 and 8 weeks of P0 protein immunization. The number of CD4⁺CD25⁺Treg in cochlea gradually increased with the prolongation of immunization time, but the expression of Foxp3 gene in cochlea gradually decreased over time. After intravenous transplantation of CD4⁺CD25⁺Treg in AN rats, the threshold of ABR response decreased, and DPOAE had no significant change. The number of spiral ganglion neurons in cochlea increased, and hair cells had no significant change under electron microscope. Conclusions: The decrease in the number and function of CD4⁺CD25⁺Treg reduces its inhibitory effect on autoimmune response and promotes the occurrence of autoimmune auditory neuropathy in AN rats. Adoptive transfer of CD4⁺CD25⁺Treg can reduce the autoimmune response and promote the recovery of autoimmune auditory neuropathy.

Light-Induced Mott-Insulator-to-Metal Phase Transition in Ultrathin Intermediate-Spin Ferromagnetic Perovskite Ruthenates

Light control of emergent quantum phenomena is a widely used external stimulus for quantum materials. Generally, perovskite strontium ruthenate SrRuO₃ has an itinerant ferromagnetism with a low-spin state. However, the phase of intermediate-spin (IS) ferromagnetic metallic state has never been seen. Here, by means of UV-light irradiation, a photocarrier-doping-induced Mott-insulator-to-metal phase transition is shown in a few atomic layers of perovskite IS ferromagnetic SrRuO_{3- δ} . This new metastable IS metallic phase can be reversibly regulated due to the convenient photocharge transfer from SrTiO₃ substrates to SrRuO_{3- δ} ultrathin films. These dynamical mean-field theory calculations further verify such photoinduced electronic phase transformation, owing to oxygen vacancies and orbital reconstruction. The optical manipulation of charge-transfer finesse is an alternative pathway toward discovering novel metastable phases in strongly correlated systems and facilitates potential light-controlled device applications in optoelectronics and spintronics.

Large Exchange Bias Effect and Coverage-Dependent Interfacial Coupling in CrI3/MnBi2Te4 van der Waals Heterostructures

Igniting interface magnetic ordering of magnetic topological insulators by building a van der Waals heterostructure can help to reveal novel quantum states and design functional devices. Here, we observe an interesting exchange bias effect, indicating successful interfacial magnetic coupling, in CrI₃/MnBi₂Te₄ ferromagnetic insulator/antiferromagnetic topological insulator (FMI/AFM-TI) heterostructure devices. The devices originally exhibit a negative exchange bias field, which decays with increasing temperature and is unaffected by the back-gate voltage. When we change the device configuration to be half-covered by CrI₃, the exchange bias becomes positive with a very large exchange bias field exceeding 300 mT. Such sensitive manipulation is explained by the competition between the FM and AFM coupling at the interface of CrI₃ and MnBi₂Te₄, pointing to coverage-dependent interfacial magnetic interactions. Our work will facilitate the development of topological and antiferromagnetic devices.

The association between dietary selenium intake and Hashimoto's thyroiditis among US adults: National Health and Nutrition Examination Survey (NHANES), 2007-2012

BACKGROUND

Selenium has been shown to influence the pathological processes and physiological functions of thyroid. Although growing evidence has shown that selenium can improve the treatment of Hashimoto's thyroiditis (HT), there is a need to evaluate the association between dietary selenium intake and HT in a large cross-sectional study. This study explored the association between dietary selenium intake and HT based on the National Health reand Nutrition Examination Survey (NHANES) database (2007-2012).

METHODS

A total of 8756 of 30,442 participants were included in the study. Dietary selenium intake was the independent variable, while HT was the dependent variable. In addition, the relative importance of the selected variables was determined using the XGBoost model. A smooth curve was constructed based on the fully adjusted model to investigate the potential linear relationship between dietary selenium intake and HT. Smooth curves were also constructed to explore the linear/non-linear relationship between dietary selenium intake and thyroid peroxidase antibody (TPOAb)/ thyroglobulin antibody (TgAb).

RESULTS

The mean age of the enrolled participants was 44.35 years (± 20.92). The risk of HT was significantly reduced by a 35% per-unit increase in dietary selenium intake after fully adjusting for covariates according to the model (log2-transformed data; OR 0.65; 95% CI 0.51, 0.83). The XGBoost model revealed that dietary selenium intake was the most important variable associated with Hashimoto's thyroiditis. Dietary selenium intake (Log2-transformed) was negatively correlated with TPOAb levels [- 16.42 (- 22.18, - 10.65), P < 0.0001], while a non-linear relationship was observed between dietary selenium intake and TgAb with an inflection point of 6.58 (95.67 μg, Log2-transformed).

CONCLUSION

Dietary selenium intake is independently and inversely associated with HT risk. Moreover, dietary selenium intake is negatively correlated with TPOAb levels and non-linearly correlated with TGAb levels. Therefore, dietary selenium intake may be a safe and low-cost alternative for the prevention and treatment of HT.

Electrical devices designed based on inorganic clusters

The idea of exploring the bottom brink of material science has been carried out for more than two decades. Clusters science is the frontmost study of all nanoscale structures. Being an example of 0-dimensional quantum dot, nanocluster serves as the bridge between atomic and conventionally understood solid-state physics. The forming mechanism of clusters is found to be the mutual effects of electronic and geometric configuration. It is found that electronic shell structure influences the properties and geometric structure of the cluster until its size becomes larger, where electronic effects submerge in geometric structure. The discrete electronic structures depend on the size and conformation of clusters, which can be controlled artificially for potential device applications. Especially, small clusters with a size of 1-2 nm, whose electronic states are possibly discrete enough to overcome thermal fluctuations, are expected to build a single-electron transistor with room temperature operation. However, exciting as the progress may be seen, cluster science still falls within the territory of merely the extension of atomic and molecular science. Its production rate limits the scientific and potential application research of nanoclusters. It is suggested in this review that the mass-produce ability without losing the atomic precision selectivity would be the milestone for nanoclusters to advance to material science.

Observation of Magnetism-Induced Topological Edge State in Antiferromagnetic Topological Insulator MnBi4Te7

Breaking time reversal symmetry in a topological insulator may lead to quantum anomalous Hall effect and axion insulator phase. MnBi₄Te₇ is a recently discovered antiferromagnetic topological insulator with T_N ∼ 12.5 K, which is composed of an alternatively stacked magnetic layer (MnBi₂Te₄) and nonmagnetic layer (Bi₂Te₃). By means of scanning tunneling spectroscopy, we clearly observe the electronic state present at a step edge of a magnetic MnBi₂Te₄ layer but absent at nonmagnetic Bi₂Te₃ layers at 4.5 K. Furthermore, we find that as the temperature rises above T_N the edge state vanishes, while the point defect induced state persists upon an increase in temperature. These results confirm the observation of magnetism-induced edge states. Our analysis based on an axion insulator theory reveals that the nontrivial topological nature of the observed edge state.

The Status of Iodine Nutrition after Removing Iodized Salt in High Water Iodine Regions: a Cross-sectional Study in China

Currently, the removal of iodized salt is carried out in high water iodine regions. The present situation of iodine nutrition and the prevalence of thyroid diseases in such regions have not been clearly elucidated. This study aimed to figure out these problems to help render effective measures for cases of abnormal iodine nutrition status. A cross-sectional study was carried out in four areas of Jining and Heze, Shandong Province, China, with different water iodine concentrations (WIC). In total, 1344 adults were enrolled in this study, and data related to their iodine nutrition, thyroid function, and thyroid ultrasonography were collected. Subjects were grouped according to WIC, urine iodine concentration (UIC), serum iodine concentration (SIC), and combined UIC and SIC for analysis. Iodine levels were in excess in the 100 μg/L ≤ WIC < 300 μg/L and WIC ≥ 300 μg/L areas. Compared with the control WIC group (10-100 μg/L), the WIC ≥ 300 μg/L group had a higher prevalence of thyroid autoimmunity (TAI, 21.25% vs. 13.19%, P <0.05), subclinical hypothyroidism (SH, 20.20% vs. 11.96%, P < 0.05), thyroid nodules (TN, 31.75% vs. 18.71%, P < 0.05), and thyroid dysfunction (23.62% vs. 12.26%, P < 0.05). Compared with the UIC control group (100-300 μg/L), high UIC group (≥ 800 μg/L) had a higher prevalence of TN (33.75% vs. 21.14%, P < 0.05) and thyroid dysfunction (25% vs. 14.47%, P < 0.05). Next, compared with the control SIC group (50-110 μg/L), high SIC group (≥ 110 μg/L) had a higher prevalence of TAI (33.80% vs. 14.47%, P < 0.05), SH (23.94% vs. 14.30%, P < 0.05), and thyroid dysfunction (33.80% vs. 15.29%, P < 0.05). Finally, subjects with the highest UIC and the highest SIC also had a higher prevalence of TAI (25.92% vs. 10.97%, P < 0.05), SH (23.45% vs. 10.97%, P < 0.05), TN (34.56% vs. 15.85%, P < 0.05), and thyroid dysfunction (27.16% vs. 13.41%, P < 0.05) than subjects with middle iodine levels. The iodine nutrition of subjects in the WIC ≥ 300 μg/L areas was still in excess after removing iodized salt from their diets. High levels of iodine also increased the prevalence of TAI, SH, TN, and thyroid dysfunction in those areas. Simply removing iodized salt may not be sufficient for high water iodine regions.

Characterization of CwlC, an autolysin, and its role in mother cell lysis of Bacillus thuringiensis subsp. israelensis

Bacillus thuringiensis subsp. israelensis (Bti) has been proven to efficiently control mosquitoes, of which many species are important vectors of human disease. The larvicidal action is attributed to the parasporal crystals formed in the sporulating cells and released upon cell autolysis. In this study, a sporulation-specific cwlC gene that encodes an N-acetylmuramoyl-_L -alanine amidase was characterized in Bti strain Bt-59. CwlC was the only cell wall hydrolase in Bti found to contain both MurNAc-LAA and Amidase02_C domains. A recombinant CwlC-His protein was able to digest the Bacillus cell wall. Deletion of the cwlC gene delayed Bti mother cell lysis without impacting vegetative growth or insecticidal efficacy. Transcriptional analyses indicated that cwlC was expressed at the late sporulation stage and was controlled by SigK. Two other cell wall hydrolase genes, cwlB and cwlE, with high expression levels at T₁₄ in Bt-59, were also identified. Like cwlC, cwlB expression was controlled by SigK; in contrast, cwlE was found not to be under the control of this sigma factor and unlike the other two, its gene was found to be plasmid encoded.

Tumor-stroma ratio is a crucial histological predictor of occult cervical lymph node metastasis and survival in early-stage (cT1/2N0) oral squamous cell carcinoma

Occult cervical lymph node metastasis is a significant prognostic factor in patients with early-stage (cT1/2N0) oral squamous cell carcinoma (OSCC). The aim of this study was to investigate the potential value of the tumor-stroma ratio (TSR) as a histological predictor of occult cervical metastasis and survival in early-stage OSCC. This retrospective study included 151 patients who underwent excision of the primary lesion and elective neck dissection from 2013 to 2017. The clinicopathological features of the tumor, risk factors associated with occult neck metastasis, and prognostic factors for overall survival (OS) and disease-free survival (DFS) were studied. A significant correlation of TSR (P = 0.009) was found with occult neck metastasis in the multivariate logistic regression model. Multivariate Cox proportional hazards regression analysis showed that the TSR (P = 0.002) and perineural invasion (P = 0.011) were associated with OS. Occult neck metastasis (P = 0.032) was associated with DFS. These findings indicate that assessment of the TSR might be useful in prognostication for early-stage OSCC patients. Moreover, the TSR is effective in allowing an accurate evaluation of the risk of occult neck metastasis, and this may be easily applicable in the routine pathological diagnosis and clinical decision-making for elective neck dissection.

Disorder-Induced Material-Insensitive Optical Response in Plasmonic Nanostructures: Vibrant Structural Colors from Noble Metals

Materials show various responses to incident light, owing to their unique dielectric functions. A well-known example is the distinct colors displayed by metals, providing probably the simplest method to identify gold, silver, and bronze since ancient times. With the advancement of nanotechnology, optical structures with feature sizes smaller than the optical wavelength have been routinely achieved. In this regime, the optical response is also determined by the geometry of the nanostructures, inspiring flourishing progress in plasmonics, photonic crystals, and metamaterials. Nevertheless, the nature of the materials still plays a decisive role in light-matter interactions, and this material-dependent optical response is widely accepted as a norm in nanophotonics. Here, a counterintuitive system-plasmonic nanostructures composed of different materials but exhibiting almost identical reflection-is proposed and realized. The geometric disorder embedded in the system overwhelms the contribution of the material properties to the electrodynamics. Both numerical simulations and experimental results provide concrete evidence of the insensitivity of the optical response to different plasmonic materials. The same optical response is preserved with various materials, providing great flexibility of freedom in material selection. As a result, the proposed configuration may shed light on novel applications ranging from Raman spectroscopy, photocatalysis, to nonlinear optics.

Pcsk9 Knockout Aggravated Experimental Apical Periodontitis via LDLR

Apical periodontitis (AP), an inflammatory lesion around the apex of tooth roots, is mostly caused by dental pulp infection. Proprotein convertase subtilisin/kexin type 9 (PCSK9) plays a vital role in regulating cholesterol homeostasis by targeting low-density lipoprotein receptor (LDLR) and participates in bacterium-induced chronic periodontitis. However, the roles of PCSK9 in AP are unknown. Here, we investigated its role in AP by using Pcsk9^-/- mice. Micro-computed tomography scanning and histological staining revealed that the periapical bone loss of Pcsk9^-/- mice was greater than that of wild-type (WT) mice, and increased expression of inflammation-related factors tumor necrosis factor α (TNF-α) and interleukin (IL)-6 was also observed. Immunofluorescence staining and quantitative real-time polymerase chain reaction showed PCSK9 expression in bone marrow macrophages (BMMs) was increased after treatment with lipopolysaccharide (LPS). This finding was consistent with the in vivo results that the expression level of PCSK9 in exposed WT mice increased compared with that in unexposed WT mice. After LPS challenge, the expression levels of TNF-α, IL-1β, and IL-6 in BMMs were increased, and Pcsk9 knockout aggravated the expression of these inflammatory factors. The number of osteoclasts positive for tartrate-resistant acid phosphatase staining around the apical lesion in Pcsk9^-/- mice was higher than that in WT mice. Then BMMs underwent the osteoclast differentiation. Pcsk9 knockout BMMs induced increased and larger osteoclasts. While this effect of Pcsk9 knockout was abolished by the addition of Ldlr small interfering RNA, revealing that Pcsk9 knockout increased osteoclastogenesis was dependent on the LDLR. Immunohistochemistry staining showed increased expression level of LDLR in exposed Pcsk9^-/- periapical areas. In vitro experiments showed that LPS promoted the expression level of LDLR in Pcsk9^-/- BMMs and increased osteoclast formation ability, indicating that LPS promoted the elevation of osteoclasteogenesis caused by the Pcsk9 knockout. In conclusion, Pcsk9 deficiency aggravated the inflammatory response and promoted the osteoclastogenesis in an LDLR-dependent manner in AP experimental mice.

The cross-talk of NLRP3 inflammasome activation and necroptotic hepatocyte death in acetaminophen-induced mice acute liver injury

Overdose acetaminophen (APAP) can result in severe liver injury, which is responsible for nearly half of drug-induced liver injury in western countries. Previous studies have found that there existed massive hepatocellular necrosis and severe inflammatory response in APAP-induced liver injury. However, the mechanistic linkage between necroptosis and NLRP3 inflammasome pathway in APAP-induced hepatotoxicity remains poorly understood. In order to investigate the relationship between inflammation and hepatocytes death in APAP hepatotoxicity, a time-course model for APAP hepatotoxicity in C57/BL6 mice was established by intraperitoneal (i.p) injection of 300 mg/kg APAP in this study. The activity of serum enzymes and pathological changes of APAP-treated mice were evaluated, and the critical molecules in necroptosis and NF-κB-NLRP3 inflammasome signaling pathway were determined by immunoblot and immunofluorescence analysis. The results demonstrated that APAP overdose resulted in a severe liver injury. Furthermore, the expression of critical molecules in NLRP3 inflammasome and necroptosis pathways peaked at 12-24 h, and then was decreased gradually, which is consistent with the pattern of pathological injury induced by APAP. Our further investigation found that the level of IL-1β in mouse liver was closely correlated with the level of phosphorylated MLKL following exposure to APAP. Furthermore, inhibition of necroptosis with necrostatin-1 significantly suppressed the activation of NLRP3 inflammasome signaling. Taken together, our results highlighted that the cross-talk between necroptosis and NLRP3 inflammasome played a critical role for promoting APAP-induced liver injury. Inhibition of the interaction of inflammation and necroptosis by pharmaceutical methods may represent a promising therapeutic strategy for APAP-induced liver injury.

Colossal Terahertz Photoresponse at Room Temperature: A Signature of Type-II Dirac Fermiology

The discovery of Dirac semimetal has stimulated bourgeoning interests for exploring exotic quantum-transport phenomena, holding great promise for manipulating the performance of photoelectric devices that are related to nontrivial band topology. Nevertheless, it still remains elusive on both the device implementation and immediate results, with some enhanced or technically applicable electronic properties signified by the Dirac fermiology. By means of Pt doping, a type-II Dirac semimetal Ir_1-xPt_xTe₂ with protected crystal structure and tunable Fermi level has been achieved in this work. It has been envisioned that the metal-semimetal-metal device exhibits an order of magnitude performance improvement at terahertz frequency when the Fermi level is aligned with the Dirac node (i.e., x ∼ 0.3) and a room-temperature photoresponsivity of 0.52 A·W^-1 at 0.12 THz and 0.45 A·W^-1 at 0.3 THz, which benefited from the excitation of type-II Dirac fermions. Furthermore, van der Waals integration with Dirac semimetals exhibits superb performance with noise equivalent power less than 24 pW·Hz^-0.5, rivaling the state-of-the-art detectors. Our work provides a route to explore the nontrivial topology of Dirac semimetal for addressing targeted applications in imaging and biomedical sensing across a terahertz gap.

Reversible engineering of topological insulator surface state conductivity through optical excitation

Despite the broadband response, limited optical absorption at a particular wavelength hinders the development of optoelectronics based on Dirac fermions. Heterostructures of graphene and various semiconductors have been explored for this purpose, while non-ideal interfaces often limit the performance. The topological insulator (TI) is a natural hybrid system, with the surface states hosting high-mobility Dirac fermions and the small-bandgap semiconducting bulk state strongly absorbing light. In this work, we show a large photocurrent response from a field effect transistor device based on intrinsic TI Sn-Bi_1.1Sb_0.9Te₂S (Sn-BSTS). The photocurrent response is non-volatile and sensitively depends on the initial Fermi energy of the surface state, and it can be erased by controlling the gate voltage. Our observations can be explained with a remote photo-doping mechanism, in which the light excites the defects in the bulk and frees the localized carriers to the surface state. This photodoping modulates the surface state conductivity without compromising the mobility, and it also significantly modify the quantum Hall effect of the surface state. Our work thus illustrates a route to reversibly manipulate the surface states through optical excitation, shedding light into utilizing topological surface states for quantum optoelectronics.

The synergistic antifungal activity of resveratrol with azoles against Candida albicans

Candida albicans is one of the most common clinical pathogenic microorganisms and it is becoming a serious health threat, particularly to immunocompromised populations. Drug resistance of Candida species has also frequently emerged, and combination therapy for fungal infections has attracted considerable attention. In this study, we established the Qinling Mountains myxobacterial secondary metabolites library and a synergic assay in combination with ketoconazole against C. albicans was introduced for metabolites screening. Two active compounds with synergic anticandidal activities were obtained, which were identified as trans-resveratrol and cis-resveratrol. According to our study, resveratrol can reduce the dosage to 1/64 of ketoconazole as well as itraconazole. Furthermore, synergistic anticandidal activity of resveratrol combined with azoles was verified against a panel of clinical C. albicans isolates, and the combination strategy enhanced the azoles susceptibility of three fluconazole-resistant isolates. These findings suggest that resveratrol enhances the efficacy of azoles and provides a promising application in therapy of C. albicans infection.

A Gd@C82 single-molecule electret

Electrets are dielectric materials that have a quasi-permanent dipole polarization. A single-molecule electret is a long-sought-after nanoscale component because it can lead to miniaturized non-volatile memory storage devices. The signature of a single-molecule electret is the switching between two electric dipole states by an external electric field. The existence of these electrets has remained controversial because of the poor electric dipole stability in single molecules. Here we report the observation of a gate-controlled switching between two electronic states in Gd@C₈₂. The encapsulated Gd atom forms a charged centre that sets up two single-electron transport channels. A gate voltage of ±11 V (corresponding to a coercive field of ~50 mV Å^-1) switches the system between the two transport channels with a ferroelectricity-like hysteresis loop. Using density functional theory, we assign the two states to two different permanent electrical dipole orientations generated from the Gd atom being trapped at two different sites inside the C₈₂ cage. The two dipole states are separated by a transition energy barrier of 11 meV. The conductance switching is then attributed to the electric-field-driven reorientation of the individual dipole, as the coercive field provides the necessary energy to overcome the transition barrier.

Plasmonic evolution of atomically size-selected Au clusters by electron energy loss spectrum

The plasmonic response of gold clusters with atom number (N) = 100–70 000 was investigated using scanning transmission electron microscopy-electron energy loss spectroscopy. For decreasing N, the bulk plasmon remains unchanged above N = 887 but then disappears, while the surface plasmon firstly redshifts from 2.4 to 2.3 eV above N = 887 before blueshifting towards 2.6 eV down to N = 300, and finally splitting into three fine features. The surface plasmon's excitation ratio is found to follow N^0.669, which is essentially R². An atomically precise evolution picture of plasmon physics is thus demonstrated according to three regimes: classical plasmon (N = 887–70 000), quantum confinement corrected plasmon (N = 300–887) and molecule related plasmon (N < 300).

Effects of targeted hydration on risk of major adverse renal and cardiac events: a systematic review and meta-analysis of randomized controlled trials

Background

Inconsistent results have been published that have evaluated the preventive effect of targeted hydration in major adverse renal and cardiac events among patients exposed to contrast agents.

Methods

Online databases were searched up to October, 2019, for randomized controlled trials (RCTs). The primary outcome was the incidence of contrast-induced acute kidney injury (CI-AKI), and the secondary outcomes were all-cause in-hospital mortality, all-cause long-term mortality, requirement for dialysis, acute pulmonary edema and stroke/transient ischemic attack (TIA).

Results

9 high quality trials were identified including 2424 patients. Overall, compared with general hydration, targeted hydration significantly reduced the incidence of CI-AKI by 58% (RR 0.42; 95% CI: 0.33–0.54, p&lt;0.01), the requirement for dialysis by 68% (RR 0.32, 95% CI: 0.17–0.62, p&lt;0.01) and the all-cause long-term mortality by 55% (RR 0.45; 95% CI: 0.26–0.76, p&lt;0.01). The effect on all-cause in-hospital mortality was not statistically significant. The effect on acute pulmonary edema and stroke/TIA also showed no difference between two groups (RR: 0.54, 95% CI: 0.28–1.03, p=0.18; RR: 0.61, 95% CI: 0.14–2.61, p=0.49, respectively). Trial sequential analysis confirmed that an additional 3900 study participants would need to be recruited to demonstrate a statistically significant improvement for all-cause in-hospital mortality.

Conclusions

Targeted hydration likely reduces the incidence of CI-AKI, dialysis and all-cause long-term mortality in patients exposed to contrast agents. However, further independent high-quality RCTs should elucidate the effectiveness and safety of this prophylactic strategy in interventional cardiology.

Funding Acknowledgement

Type of funding source: None

Global risk factors of contrast-induced acute kidney injury: systematic review and meta-analysis

Background

Administration of iodinated contrast is common but may be associated with contrast-induced acute kidney injury (CI-AKI), particularly in at-risk patients. There is no recent systematic review of potentially modifiable risk factors.

Methods

We searched MEDLINE, Embase and the Cochrane Database of Systematic Reviews (to 30 th June 2019) for observational studies assessing risk factors associated with CI-AKI. Twelve potentially modifiable risk factors were finally included in this thematic review and meta-analysis. Random or fixed meta-analysis was performed to derive the adjusted odds ratio (aOR), and the population attributable risk (PAR) was calculated for each risk factor globally and by region.

Findings

We included 157 studies (2,297,863 participants). The global incidence of CI-AKI was 5.4%. The potentially modifiable risk factors included high contrast volume (PAR 33%), eight cardiovascular risk factors (diuretic use, multivessel coronary artery disease, acute coronary syndrome, hypertension, hypotension, heart failure, reduced left ventricular ejection fraction and intra-aortic balloon pump use) (combined PAR 76.2%) and three noncardiovascular risk factors (renal dysfunction, diabetes mellitus and anaemia) (combined PAR 47.4%) with geographical differences.

Bubble chart of the 12 risk factors

Funding Acknowledgement

Type of funding source: Public Institution(s). Main funding source(s): National Science Foundation of China

Identifying Native Point Defects in the Topological Insulator Bi2Te3

We successfully identified native point defects that occur in Bi₂Te₃ crystals by combining high-resolution bias-dependent scanning tunneling microscopy and density functional theory based calculations. As-grown Bi₂Te₃ crystals contain vacancies, antisites, and interstitial defects that may result in bulk conductivity and therefore may change the insulating bulk character. Here, we demonstrate the interplay between the growth conditions and the density of different types of native near-surface defects. In particular, scanning tunneling spectroscopy reveals the dependence on not only the local atomic environment but also on the growth kinetics and the resulting sample doping from n-type toward intrinsic crystals with the Fermi level positioned inside the energy gap. Our results establish a bias-dependent STM signature of the Bi₂Te₃ native defects and shed light on the link between the native defects and the electronic properties of Bi₂Te₃, which is relevant for the synthesis of topological insulator materials and the related functional properties.

A novel FZD6 mutation revealed the cause of cleft lip and/or palate in a Chinese family

Cleft lip and/or palate (CL/P) is a most common craniofacial birth defect which has multifactorial etiology. In our study, we aimed to discover the underlying etiological gene variation in a Chinese family diagnosed as non-syndromic CL/P (NSCL/P). The blood sample of the proband and her parents were detected by whole exome sequencing. The Mendelian inheritance pattern, allele frequency, variation location, function analysis and literature search were applied to filtrate and screen the mutation. Besides, the candidates were confirmed by Sanger sequencing. We meanwhile explored the conservative analysis and protein homology simulation. As a result, a start-lost mutation c.1A > GAtg/Gtg in the Frizzled-6 (FZD6) gene predicting p.Met1 was detected. The variation has not been reported before and was predicted to be harmful. The alteration caused missing of two starting amino acids that are evolutionarily conserved for FZD6 protein. Moreover, the specific structure of the mutant protein obviously changed according to the results of the homologous model. In conclusion, the results suggest c.1A > GAtg/Gtg in the FZD6 (NM_001164616) might be the genetic etiology for non-syndromic CL/P in this pedigree. Furthermore, this finding provided new etiologic information, supplementing the evidence that FZD6 is a strong potential gene for CL/P.

Long-Range Ordered Amorphous Atomic Chains as Building Blocks of a Superconducting Quasi-One-Dimensional Crystal

Crystalline and amorphous structures are two of the most common solid-state phases. Crystals having orientational and periodic translation symmetries are usually both short-range and long-range ordered, while amorphous materials have no long-range order. Short-range ordered but long-range disordered materials are generally categorized into amorphous phases. In contrast to the extensively studied crystalline and amorphous phases, the combination of short-range disordered and long-range ordered structures at the atomic level is extremely rare and so far has only been reported for solvated fullerenes under compression. Here, a report on the creation and investigation of a superconducting quasi-1D material with long-range ordered amorphous building blocks is presented. Using a diamond anvil cell, monocrystalline (TaSe₄ )₂ I is compressed and a system is created where the TaSe₄ atomic chains are in amorphous state without breaking the orientational and periodic translation symmetries of the chain lattice. Strikingly, along with the amorphization of the atomic chains, the insulating (TaSe₄ )₂ I becomes a superconductor. The data provide critical insight into a new phase of solid-state materials. The findings demonstrate a first ever case where superconductivity is hosted by a lattice with periodic but amorphous constituent atomic chains.

Beam generation and structural optimization of size-selected Au923 clusters

A size-selected beam of Au_923±20 clusters is generated in a gas-phase condensation cluster source equipped with a lateral time-of-flight mass selector. The beam current reaches up to 9.13 nA for small clusters and 80 pA for Au_923±20 clusters, which are then analyzed using a scanning transmission electron microscope. Four types of metastable structures are observed for the Au_923±20 clusters, including ino-decahedron (Dh), cuboctahedron and icosahedron (Ih). The proportion of bulk-favorable cuboctahedron (i.e. face center cubic (Fcc)) structure takes up only 10-20%, while the penta-rotating symmetrical structures (Dh/Ih) are the dominant ones which take up over three quarters. Changing the beam condition may optimize the clusters from Dh-dominant to the Ih-dominant phase, which paves the way towards nanoparticle control beyond the diameters.

The Material Efforts for Quantized Hall Devices Based on Topological Insulators

A topological insulator (TI) is a kind of novel material hosting a topological band structure and plenty of exotic topological quantum effects. Achieving quantized electrical transport, including the quantum Hall effect (QHE) and the quantum anomalous Hall effect (QAHE), is an important aspect of realizing quantum devices based on TI materials. Intense efforts are made in this field, in which the most essential research is based on the optimization of realistic TI materials. Herein, the TI material development process is reviewed, focusing on the realization of quantized transport. Especially, for QHE, the strategies to increase the surface transport ratio and decrease the threshold magnetic field of QHE are examined. For QAHE, the evolution history of magnetic TIs is introduced, and the recently discovered magnetic TI candidates with intrinsic magnetizations are discussed in detail. Moreover, future research perspectives on these novel topological quantum effects are also evaluated.

Polymorphisms of 19 Autosomal STR Loci in Sichuan Han Population and Their Forensic Application

Objective To investigate the allele distribution, population genetics parameters and genetic analysis of neighboring populations of 19 autosomal STR loci in Sichuan Han population, and to evaluate their forensic application value. Methods The Goldeneye?? DNA ID system 20A was used to perform multiplex PCR amplification and allelic gene typing of 19 STR loci in 1 201 unrelated Han individuals from Sichuan Province. Allele frequencies and population genetics parameters were calculated. The Nei's genetic distances between Sichuan Han population and 12 previously reported populations were analyzed. Multidimensional scaling and principal component analysis were carried out and phylogenetic trees were also constructed. Results The heterozygosity of 19 STR loci ranged from 0.617 0 to 0.915 1, their discrimination power ranged from 0.777 4 to 0.986 5, matching probability ranged from 0.013 5 to 0.222 6, polymorphism information content ranged from 0.546 4 to 0.910 5, probability of exclusion ranged from 0.311 8 to 0.826 3 （triplet） and from 0.197 9 to 0.712 1 （biplet）, and no significant deviations from Hardy-Weinberg equilibrium were observed. Based on the results of multidimensional scaling, principal component analysis and phylogenetic trees of the genetic distances between Sichuan Han population and the other 12 populations, Sichuan Han population was closest to Hubei Han population and was farthest to Xinjiang Uygur population. Conclusion The 19 autosomal STR loci showed a high polymorphism and discriminating ability in Sichuan Han population, which can provide a data foundation for personal identification, paternity test and population genetics study.

[Transcriptome profiling of differentiated lenses through RNA sequencing]

Objective: To gain insight into the transcriptional landscape including mRNA, long non-coding RNA (lncRNA), and circular RNA (circRNA) of the differentiated lens. Methods: Experiment research. The total RNAs of the differentiated lenses were extracted and purified. Total RNAs of 16-week, 23-week, and 25-week differentiated lenses were then sequenced using Illumina HiSeq 2500, and analyzed using bioinformatics tools. The top expressed and differentially expressed mRNAs and lncRNAs were screened. The expressions of overlap genes among the 16-week, 23-week, and 25-week lenses were analyzed by Venn diagram. The expression tendency of lens-specific genes was obtained and verified with real-time polymerase chain reaction. Results: A total of 67 518 311 mapped reads were obtained from differentiated lenses at 16 weeks, 99 440 160 at 23 weeks, and 67 262 320 at 25 weeks. The gene overlap expression analysis showed 740 of the top 1 000 highly expressed mRNAs, 170 of the top 300 highly expressed lncRNAs, and 69 of the top 100 highly expressed circRNAs overlapping expressed in lenses at 16, 23, and 25 weeks, respectively. Lens specific gene expression analysis revealed that the expression of crystallin (CRY) AA, CRYGA, CRYGB, CRYGC, CRYGD, CRYGEP, and CRYGS was upregulated, while the expression of gap junction (GJ) A3 and GJA8 was downregulated with the differentiation of lenses. Conclusion: The lens transcriptome profile shows that more than half of the high expressed mRNA, lncRNA and circRNA at different differentiation stages are overlapping expressed, and all of them have high expression of lens specific protein genes, such as CRY, GJ etc. (Chin J Ophthalmol, 2020, 56: 356-363).

Hierarchical structural complexity in atomically precise nanocluster frameworks

The supramolecular chemistry of nanoclusters is a flourishing area of nano-research; however, the controllable assembly of cluster nano-building blocks in different arrays remains challenging. In this work, we report the hierarchical structural complexity of atomically precise nanoclusters in micrometric linear chains (1D array), grid networks (2D array) and superstructures (3D array). In the crystal lattice, the Ag29(SSR)12(PPh3)4 nanoclusters can be viewed as unassembled cluster dots (Ag29–0D). In the presence of Cs+ cations, the Ag29(SSR)12 nano-building blocks are selectively assembled into distinct arrays with different oxygen-carrying solvent molecules―Cs@Ag29(SSR)12(DMF)x as 1D linear chains (Ag29–1D), Cs@Ag29(SSR)12(NMP)x as 2D grid networks (Ag29–2D), and Cs@Ag29(SSR)12(TMS)x as 3D superstructures (Ag29–3D). Such self-assemblies of these Ag29(SSR)12 units have not only been observed in their crystalline state, but also in their amorphous state. Due to the diverse surface structures and crystalline packing modes, these Ag29-based assemblies manifest distinguishable optical absorptions and emissions in both solutions and crystallized films. Furthermore, the surface areas of the nanocluster crystals are evaluated, the maximum value of which occurs when the cluster nano-building blocks are assembled into 2D arrays (i.e. Ag29–2D). Overall, this work presents an exciting example of the hierarchical assembly of atomically precise nanoclusters by simply controlling the adsorbed molecules on the cluster surface.

Rendering hydrophobic nanoclusters water-soluble and biocompatible

Hydrophobic and hydrophilic nanoclusters embody complementary superiorities. The means to amalgamate these superiorities, i.e., the atomic precision of hydrophobic clusters and the water dissolvability of hydrophilic clusters, remains challenging. This work presents a versatile strategy to render hydrophobic nanoclusters water-soluble-the micellization of nanoclusters in the presence of solvent-conjoined Na+ cations-which overcomes the above major challenge. Specifically, although [Ag29(SSR)12(PPh3)4]3- nanoclusters are absolutely hydrophobic, they show good dissolvability in aqueous solution in the presence of solvent-conjoined Na+ cations (Na1(NMP)5 or Na3(DMF)12). Such cations act as both counterions of these nanoclusters and surface cosolvent of cluster-based micelles in the aqueous phase. A combination of DLS (dynamic light scattering) and aberration-corrected HAADF-STEM (high angle annular dark field detector scanning transmission electron microscopy) measurements unambiguously shows that the phase-transfer of hydrophobic Ag29 into water is triggered by the micellization of nanoclusters. Owing to the excellent water solubility and stability of [Ag29(SSR)12(PPh3)4]3-[Na1(NMP)5]3 + in H2O, its performance in cell staining has been evaluated. Furthermore, the general applicability of the micellization strategy has been verified. Overall, this work presents a convenient and efficient approach for the preparation of cluster-based, biocompatible nanomaterials.