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ObjectiveTo compare the application value of three image post-processing techniques volume rendering （VR）, multiplanar reformation （MPR） and curved planar reformation （CPR） in the identification of rib fracture malunion.MethodsThe types and numbers of rib fracture malunion in 75 patients were recorded, and the sensitivity, specificity, accuracy and Youden index of VR, MPR and CPR in the diagnosis of rib fracture malunion were compared. Receiver operator characteristic （ROC） curve was drawn and area under the curve （AUC） was calculated, and the detection rates of three image post-processing techniques for different types of rib fracture malunion were compared.ResultsA total of 243 rib fractures were malunion in 75 patients. The diagnostic sensitivity of VR, MPR and CPR for rib fracture malunion was 52.67%, 79.84% and 91.36%, the specificity was 99.58%, 97.89% and 99.15%, the accuracy was 83.66%, 91.76% and 96.51%, the Youden index was 0.52, 0.78 and 0.91, the AUC was 0.761, 0.889 and 0.953, respectively. Compared with VR, there were statistically significant differences in the number of broken rib end misalignment over 1/3, broken rib end overlap, broken rib end angulation and intercostal bridge detected in MPR （P

[Objective] The distribution status and availability of soil selenium in three jujube orchards in Minqin County, Gansu Province was analyzed in order to provide a theoretical basis for the development of the selenium-enriched jujube industry. [Methods] The contents of total selenium and various forms of selenium in the 0—60 cm soil layer in three jujube orchards of Minqin County were measured by a method of successive extraction. Jujube distribution characteristics and availability were determined. [Results] ① The total selenium content was 24—520 μg/kg (average was 210.625 μg/kg), suggesting that total soil selenium was not deficient. ② Total soil selenium content increasingly declined with increasing soil depth in the 0—60 cm soil layer, with values in the three orchards following the order of Liugou>Zhangba>Xinguoyuan. According to the partition criterion for soil selenium content, the surface soil (0—20 cm) was categorized as selenium-rich; the subsurface soil (20—40 cm) was selenium-rich and selenium-poor; and the bottom soil layer (40—60 cm) was selenium-rich, selenium-poor, and selenium-deficient. ③ The available selenium content was 42.5 μg/kg and accounted for 20.2% of total selenium. Soluble selenium was 1.1—1.4 μg/kg, exchangeable selenium was 1.4—2.8 μg/kg. Both of these selenium forms together accounted for only 7.7% of the available selenium. The remaining available selenium was all organic selenium. ④ The available soil selenium increased with increasing number of reclamation years and followed the order of Xinguoyuan>Liugou>Zhangba among the three orchards. ⑤ The contents of total selenium, available selenium, and ineffective selenium were greater under trees than between tree rows. [Conclusion] Total selenium was not deficient in the soil of jujube orchards of Minqin County, but available selenium was deficient. Hence, development of the selenium-enriched jujube industry will require artificially supplementing soils with selenium fertilizer.

ObjectiveTo explore the relationship between the height of alveolar bone resorption and sex and age in the adolescent dentition.MethodsMulti-slice computed tomography （MSCT） was used to measure the height of alveolar bone resorption at labial, lingual, mesial and distal sites of teeth in 149 adolescents aged from 10 to 20 years. SPSS 25.0 software was used to analyze the relationship between the height of alveolar bone resorption and sex and age.ResultsThere was no significant difference in the height of alveolar bone resorption between sex （P>0.05）. The height of alveolar bone resorption was positively correlated with age in all types of teeth. The model constructed by combining the alveolar bone resorption height data of four sites （y=2.569x1+3.106x2+4.108x3+1.451x4-0.082，R2max=0.756）had a better ability to infer age than that of combining two sites （y=5.942x1+4.489x2+0.612，R2max=0.706） and a single site （R2max=0.638）.ConclusionThe height of alveolar bone resorption is positively correlated with the age of adolescents. The combination of four sites has a stronger ability to infer the relationship between the height of alveolar bone resorption and age in adolescents and has higher accuracy in practical application.

The complex non-centrosymmetric and chiral nature of helical structures endow materials that possess such motifs with unusual properties. However, despite their ubiquity in biological and organic systems, there is a severe lack of inorganic crystals that display helicity in extended lattices, where these unusual properties are expected to be most pronounced. Here, we report a new inorganic helical structure, gallium sulfur iodide (GaSI), within the exfoliable class of III-VI-VII (1:1:1) one-dimensional (1D) van der Waals (vdW) crystals. Through detailed structural analyses, including single-crystal X-ray diffraction, electron microscopy, and density functional theory (DFT), we elucidate the apparent noncrystallographic screw axis and the first example of an atomic scale helical structure bearing a squircular cross-section in GaSI. Crystallizing in the non-centrosymmetric P4̅ space group, we found that GaSI crystals exhibit pronounced second-harmonic generation. From diffuse reflectance spectroscopy, GaSI displays a sizeable bandgap of 3.69 eV, owing tostrong covalent interactions arising from the smaller sulfur atoms within the helix core. These results position GaSI as a promising exfoliable nonlinear optical material across a broad optical window.

Superplastic tensile behavior and deformation mechanism of TC18 titanium alloy were investigated by high temperature tensile test at 720-950℃ with initial strain rates of 6.7×10-5s-1-3.3×10-1s-1.The results show that under the optimal superplastic deformation condition (890℃ and 3.3×10-4s-1),the maximum elongation is 470%, the peak stress is 17.93MPa and with uniform grain size.Below the phase transus Tβ,the elongation firstly increases and then decreases.A maximum elongation of 373% is obtained at 830℃ and with initial strain rate of 3.3×10-4s-1 and the peak stress is 31.45MPa.The superplastic deformation mechanism of the TC18 titanium alloy in two-phase region is mainly grain rotation and boundary sliding,and the deformation coordination mechanism is dislocation slipping and climbing; the superplastic deformation mechanism in single phase region is intragranular dislocation motion and the deformation coordination mechanism is dynamic recovery and dynamic recrystallization.

Interfacing organic molecular groups with well-defined inorganic lattices, especially in low dimensions, enables synthetic routes for the rational manipulation of both their local or extended lattice structures and physical properties. While appreciably studied in two-dimensional systems, the influence of surface organic substituents on many known and emergent one-dimensional (1D) and quasi-1D (q-1D) crystals has remained underexplored. Herein, we demonstrate the surface functionalization of bulk and nanoscale Chevrel-like q-1D ionic crystals using In2Mo6Te6, a predicted q-1D Dirac semimetal, as the model phase. Using a series of alkyl ammonium (-NR4+; R = H, methyl, ethyl, butyl, and octyl) substituents with varying chain lengths, we demonstrate the systematic expansion of the intrachain c-axis direction and the contraction of the interchain a/b-axis direction with longer chain substituents. Additionally, we demonstrate the systematic expansion of the intrachain c-axis direction and the contraction of the interchain a/b-axis direction as the alkyl chain substituents become longer using a combination of powder X-ray diffraction and Raman experiments. Beyond the structural modulation that the substituted groups can impose on the lattice, we also found that the substitution of ammonium-based groups on the surface of the nanocrystals resulted in selective suspension in aqueous (NH4+-functionalized) or organic solvents (NOc4+-functionalized), imparted fluorescent character (Rhodamine B-functionalized), and modulated the electrical conductivity of the nanocrystal ensemble. Altogether, our results underscore the potential of organic-inorganic interfacing strategies to tune the structural and physical properties of rediscovered Chevrel-type q-1D ionic solids and open opportunities for the development of surface-addressable building blocks for hybrid electronic and optoelectronic devices at the nanoscale.

The realization of stable monolayers from 2D van der Waals (vdW) solids has fueled the search for exfoliable crystals with even lower dimensionalities. To this end, 1D and quasi-1D (q-1D) vdW crystals comprising weakly bound subnanometer-thick chains have been discovered and demonstrated to exhibit nascent physics in the bulk. Although established micromechanical and liquid-phase exfoliation methods have been applied to access single isolated chains from bulk crystals, interchain vdW interactions with nonequivalent strengths have greatly hindered the ability to achieve uniform single isolated chains. Here, we report that encapsulation of the model q-1D vdW crystal, Sb2Se3, within single-walled carbon nanotubes (CNTs) circumvents the relatively stronger c-axis vdW interactions between the chains and allows for the isolation of single chains with structural integrity. High-resolution transmission electron microscopy and selected area electron diffraction studies of the Sb2Se3@CNT heterostructure revealed that the structure of the [Sb4Se6]n chain is preserved, enabling us to systematically probe the size-dependent properties of Sb2Se3 from the bulk down to a single chain. We show that ensembles of the [Sb4Se6]n chains within CNTs display Raman confinement effects and an emergent band-like absorption onset around 600 nm, suggesting a strong blue shift of the near-infrared band gap of Sb2Se3 into the visible range upon encapsulation. First-principles density functional theory calculations further provided qualitative insight into the structures and interactions that could manifest in the Sb2Se3@CNT heterostructure. Spatial visualization of the calculated electron density difference map of the heterostructure indicated a minimal degree of electron donation from the host CNT to the guest [Sb4Se6]n chain. Altogether, this model system demonstrates that 1D and q-1D vdW crystals with strongly anisotropic vdW interactions can be precisely studied by encapsulation within CNTs with suitable diameters, thereby opening opportunities in understanding dimension-dependent properties of a plethora of emergent vdW solids at or approaching the subnanometer regime.

Precision control via molecular structure over adaptive conjugated polymer properties in aqueous environments is critical for realizing their biomedical applications. Here, we unravel the dependence of amphiphilic peptide-polydiacetylene (PDA) conjugate properties on the characteristic steric and hydrophobic contributions within peptide segments that serve as a biomimetic template for diacetylene polymerization in water. We investigated the functional impacts of molecular volume and polarity changes brought by dipeptide substitution domains on the following peptide-PDA material properties at multiple length scales: supramolecular assembly behavior, chain conformation-dependent photophysical properties, cell-material interfacing, and for the first time, bulk electrical properties of their films processed in water. A library of peptide-PDAs with systematically varied sequences show that the contributions of steric effects predominantly influence the electronic structure and resulting trends in photophysical properties, while the interplay between size and hydrophobicity of individual residues becomes more significant for higher-order assemblies affecting bulk properties. This work demonstrates sequence-tunable molecular volume and polarity as synthetic handles to rationally modulate PDA material properties across length scales, providing insights into the programmability of biomimetic conjugated polymers with adaptive functionalities.

Multi-scale organization of molecular and living components is one of the most critical parameters that regulate charge transport in electroactive systems-whether abiotic, biotic, or hybrid interfaces. In this article, an overview of the current state-of-the-art for controlling molecular order, nanoscale assembly, microstructure domains, and macroscale architectures of electroactive organic interfaces used for biomedical applications is provided. Discussed herein are the leading strategies and challenges to date for engineering the multi-scale organization of electroactive organic materials, including biomolecule-based materials, synthetic conjugated molecules, polymers, and their biohybrid analogs. Importantly, this review provides a unique discussion on how the dependence of conduction phenomena on structural organization is observed for electroactive organic materials, as well as for their living counterparts in electrogenic tissues and biotic-abiotic interfaces. Expansion of fabrication capabilities that enable higher resolution and throughput for the engineering of ordered, patterned, and architecture electroactive systems will significantly impact the future of bioelectronic technologies for medical devices, bioinspired harvesting platforms, and in vitro models of electroactive tissues. In summary, this article presents how ordering at multiple scales is important for modulating transport in both the electroactive organic, abiotic, and living components of bioelectronic systems.

Interfacial properties of a hole‐transport material (HTM) and a perovskite layer are of high importance, which can influence the interfacial charge transfer dynamics as well as the growth of perovskite bulk crystals particularly in inverted structure. The halogen bonding (XB) has been recognized as a powerful functional group to be integrated with new small molecule HTMs. Herein, a carbazole‐based halo (iodine)‐functional HTM (O1), is synthesized for the first time, demonstrating a high hole mobility and suitable energy levels that align well with those of perovskites. The strong interaction between O1 and perovskite, i.e., I···I−, induces the formation of an ordered interlayer, which are verified by both theoretical and experimental studies. Compared to the reference HTM (O2) without any halo‐function, the XB‐induced interlayer effectively enhances the interfacial charge extraction efficiency, while significantly hindering the non‐radiative charge recombination by reducing the surface traps upon the strong passivation effect. This is reflected as a big increase in the open‐circuit voltage by up to 114 mV in the fabrication of inverted devices with the highest power conversion efficiency of 22.34%. Moreover, the ordered XB‐driven interlayer at the interface of O1 and perovskite is mainly responsible for the extended lifespan under the operational conditions. [ABSTRACT FROM AUTHOR]

BN-embedded anthracenes with chiral 3,7-dimethyloctyl side chains (namely (S,S)- and (R,R)-DPBNA) have been synthesized as novel visible-blind ultraviolet-absorbing chiral materials for ultraviolet circularly polarized light (CPL) detection. Phototransistors with a p–n heterojunction configuration have been fabricated with (S,S)/(R,R)-DPBNA serving as the p-type photoactive layer and an achiral n-type polymer as the electron transport layer. Significant discrimination between left and right CPL has been observed under 365 nm CPL irradiation with an average photocurrent dissymmetry factor of 0.033, highlighting the potential of BN-embedded semiconductors for ultraviolet CPL detection. [ABSTRACT FROM AUTHOR]