Symmetry-Broken Intermolecular Charge Separation of Cationic Radicals.

A quadrupolar compound Pyr-BA with two pyrrole-type nitrogen atoms doped externally was prepared in this work. In high contrast with other π ionic radicals, its cationic radical Pyr-BA⋅+ undergoes unusual symmetry-broken charge separation (SB-CS), generating the mixed valence complex of Pyr-BA+1-q ⋅⋅⋅Pyr-BA+1+q , where q is the degree of charge transfer. Variable-temperature (VT) single-crystal analysis, absorption and EPR experiments all confirmed that aggregation and lower temperature would help to facilitate this SB-CS process. Gibbs energy calculations and gauge-including magnetically induced current simulation both validate that, for Pyr-BA⋅+ , SB-CS behavior is more favorable than the conventional dimerization mode. To the best of our knowledge, this is the first study that shows solid single-crystal evidence for spontaneous SB-CS between identical ionic radicals. Such a unique phenomenon is of great significance both in terms of fundamental aspects and uncharted material science.

Multi-Image Encryption Algorithm Based on Cascaded Modulation Chaotic System and Block-Scrambling-Diffusion.

To address the problem of a poor security image encryption algorithm based on a single chaotic map, this paper proposes a cascade modulation chaotic system (CMCS) that can generate multiple chaotic maps. On this basis, a multi-image encryption algorithm with block-scrambling-diffusion is proposed using CMCS. The algorithm makes full use of the features of CMCS to achieve the effect of one encryption at a time for images. Firstly, the key-value associated with the plaintexts is generated using a secure hash algorithm-512 (SHA-512) operation and random sequence, and the three images are fully confused by the double scrambling mechanism. Secondly, the scrambled image is converted into a bit-level matrix, and the pixel values are evenly distributed using the bit-group diffusion. Finally, the non-sequence diffusion of hexadecimal addition and subtraction rules is used to improve the security of the encryption algorithm. Experimental results demonstrate that the encryption algorithm proposed in this paper has a good encryption effect and can resist various attacks.

Effect of Surface Modification with Hydrocarbyl Groups on the Exocytosis of Nanoparticles.

Designing nanoparticles (NPs) with desirable cell type-specific exocytosis properties, say promoting their exocytosis from scavenging cell types (e.g., macrophages and endothelial cells) or suppressing their exocytosis from target disease cell types (e.g., cancer cells), improves the application of nanomedicines. However, the design parameters available for tuning the exocytosis of NPs remain scarce in the "nano-cell" literature. Here, we demonstrate that surface modification of NPs with hydrocarbyl functional groups, commonly found in biomolecules and NP-based drug carriers, is a critical parameter for tuning the exocytosis of NPs from RAW264.7 macrophages, C166 endothelial cells, and HeLa epithelial cancer cells. To exclude the effect of hydrophobicity, we prepare a collection of hydrophilic NPs that bear a gold NP (AuNP) core, a dense polyethylene glycol (PEG) shell, and different types of hydrocarbyl groups (X) that are attached to the distal end of the PEG strands (termed "Au@PEG-X NPs"). For all three cell types tested, modification of NPs with straight-chain dodecane leads to a >10-fold increase in the level of cellular uptake, drastically higher than those of all other types of X tested. However, the probability of exocytosis of NPs significantly depends on the types of cell and X. Notably, NPs modified with cyclododecanes are most likely to be exocytosed by RAW264.7 and C166 cells (but not HeLa cells), accompanied by the release of intralumenal vesicles to the extracellular milieu. These data suggest a reductionist approach for rationally assembling bionanomaterials for nanomedicine applications by using hydrocarbyl functional groups as building blocks.

Inhibition of Histone Deacetylase 6 by Tubastatin A Attenuates the Progress of Osteoarthritis via Improving Mitochondrial Function.

Because chondrocytes are the only resident cells in articular cartilage, the steady state of these cells is important for the maintenance of joint function. In various osteoarthritis diseases, chondrocytes undergo a series of pathophysiologic changes, leading to the loss of chondrocytes and the degradation of extracellular matrix (ECM). This study found that Cytoplasmic localized histone deacetylase 6 (HDAC6) is up-regulated on the articular surface in a destabilization of the medial meniscus-induced mouse osteoarthritis model. Because HDAC6 is highly related to the acetylation of tubulin and the function of the microtubule system is closely related to material transport and signal transduction, the relationship between the expression level or activity of HDAC6 and the fate of chondrocytes in vitro and in vivo were confirmed. Primary chondrocytes overexpressing DNA-HDAC6 with plasmid were constructed in vitro, and HDAC6 inhibitor Tubastatin A was selected to inhibit HDAC6 enzyme activity in vivo and in vitro. Subsequently, mitochondrial spatial arrangement, degradation of ECM, and pathological changes in joint were defined. The results indicate that overexpression of HDAC6 causes mitochondrial dysfunction and promotes reactive oxygen species production, leading to degradation of ECM. Tubastatin A treatment after osteoarthritis ameliorates the degradation of cartilage and improves the microenvironment and function of the joint. HDAC6 may be targeted to treat osteoarthritis.

Cationization of neutral small molecules by site-specific carboxylation of 10-phenyl-10H-phenothiazine in laser desorption/ionization.

It is a pre-requisite to ionize analyte molecules efficiently for detection by laser desorption/ionization mass spectrometry. Here, we report a conceptual demonstration of cationizing neutral small molecules which are typically difficult to be ionized with the traditional organic matrices due to their low proton/cation affinity values. Our strategy features generating radical cations from site-specifically carboxylated 10-(4-carboxyphenyl)-10H-phenothiazine-3,7-dicarboxylic acid (PTZ(A)2-Ph(A)) with a laser, and anchoring the chlorine ion from NaCl through covalent bond-like bridging interactions with the N/S atoms in the heterocyclic structure. This "Maverick" design allows a dramatic change of the energy landscape of analyte sodiation with an enhanced efficiency. We have synthesized two families of compounds based on the model structures of phenothiazine (PTZ) and phenoxazine (PXZ) and their carboxylated derivatives, and performed comparison between them or against the traditional organic matrices in a systematic format. We have demonstrated that PTZ(A)2-Ph(A) is outstanding as a novel MALDI matrix for the detection of oligosaccharides and amino acids, with an ultra-clean background baseline and high signal-to-noise ratios (up to dozens of times better than the traditional matrices). This work provides a new method for the cationization of neutral small molecules in a distinct mechanism, inspiring the development of next-generation matrices for sensitive detection of hard-to-be-ionized molecules by MALDI MS.

Percutaneous reduction, cannulated screw fixation and calcium sulfate cement grafting assisted by 3D printing technology in the treatment of calcaneal fractures.

BACKGROUND: Percutaneous reduction, cannulated screw fixation and calcium sulfate cement grafting (PR + CSC) for treatment of displaced and intra-articular calcaneal fractures (DIACFs) is a difficult technique, because the minimally invasive treatment has limited exposure and cannot be used to reduce articular surface under direct vision. The goal of this study was to apply 3D printing technology to preoperative planning and surgery of DIACFs, and to evaluate its effectiveness, feasibility and safety in fracture repair. METHODS: We enrolled 81 patients with DIACFs in the study from August 2015 to August 2017. Patients with DIACFs in our hospital were randomly divided into the 3D printing group (40 cases) and the conventional group (41 cases). The operation duration, blood loss volume and the number of fluoroscopy were compared. Radiological results were evaluated using radiographs and functional results were evaluated using the American Orthopedic Foot and Ankle Society (AOFAS) score. The complications were also assessed. In addition, we made a questionnaire to verify the usefulness of the 3D printed model for both doctors and patients. RESULTS: The operation duration, blood loss volume and the number of fluoroscopy in 3D printing group were significantly less than that in the conventional group. Besides, 3D printing group achieved significantly better radiological results than conventional group both postoperatively and at the final follow-up except the calcaneal width at the final follow-up. The AOFAS score in the 3D printing group was significantly higher than that in the conventional group. In addition, the questionnaire from doctors and patients exhibited high scores of overall satisfaction of the 3D printed models. As for complications, there was no significant difference among the two groups. CONCLUSION: This study suggested the clinical feasibility of PR + CSC assisted by 3D printing technology in the treatment of DIACFs. LEVEL OF EVIDENCE: II.

Characterizing the Conformational Distribution in an Amorphous Film of an Organic Emitter and Its Application in a "Self-Doping" Organic Light-Emitting Diode.

The conformational distribution and mutual interconversion of thermally activated delayed fluorescence (TADF) emitters significantly affect the exciton utilization. However, their influence on the photophysics in amorphous film states is still not known due to the lack of a suitable quantitative analysis method. Herein, we used temperature-dependent time-resolved photoluminescence spectroscopy to quantitatively measure the relative populations of the conformations of a TADF emitter for the first time. We further propose a new concept of "self-doping" for realizing high-efficiency nondoped OLEDs. Interestingly, this "compositionally" pure film actually behaves as a film with a dopant (quasi-equatorial form) in a matrix (quasi-axial form). The concentration-induced quenching that may occur at high concentrations is thus expected to be effectively relieved. The "self-doping" OLED prepared with the newly developed TADF emitter TP2P-PXZ as a neat emitting layer realizes a high maximum external quantum efficiency of 25.4 % and neglectable efficiency roll-off.

Interference Screw for the Treatment of Pediatric Flexible Flatfoot.

Flexible flatfoot is a common deformity in the pediatric population and can cause a range of symptoms and reduce the quality of life. Subtalararthroereisis may be appropriate for pediatric population whose conservative management had failed to relief their symptoms typically for at least 6 months. Subtalararthroereisis has been developed for a long time, but the use of interference screw for the treatment of pediatric flexible flatfoot has not been reported. From January, 2016 to June, 2017, we operated on 21 children (39 feet) between the ages of 8 and 14 years. The clinical assessment was based on the American Orthopedic Foot and Ankle Society (AOFAS) hind-foot scale and the Chippaux-Smirak Index (CSI) measurements. And the anatomical parameters assessment was based on the radiographs and photographs. The postoperative AOFAS scores and CSI measurements were improved compared with preoperative AOFAS scores and CSI measurements. Postoperative anatomical parameters achieved significantly better results than preoperative anatomical parameters. In conclusion, the use of interference screw in subtalararthroereisis for the treatment of pediatric flexible flatfoot deformity is an effective, simple and minimally invasive solution.

Biomechanical Analysis of a Novel Syndesmotic Plate Compared With Traditional Screw and Suture Button Fixation.

Many lateral malleolus fractures have been found to have syndesmosis injuries after anatomic reduction. The main methods for the treatment of syndesmosis injuries are screw fixation and suture-button flexible fixations. In pursuit of innovation, we have designed a novel syndesmotic plate (NSP) for simultaneous fixation of lateral malleolus fractures and distal tibiofibular syndesmosis injuries. The purpose of this study is to compare the biomechanical characteristics of the NSP to syndesmotic screw and suture-button fixations. Twelve adult cadaveric specimens were used in this experiment. Axial loading as well as rotation torque were applied in 3 different ankle positions: neutral, dorsiflexion, and plantarflexion. After the initial specimens were tested, they were made into a pronation-abduction III fracture model as described by Lauge-Hansen. Subsequently, the specimens were fixed sequentially using a distal fibular anatomic locking plate (DFALP) combined with syndesmotic screws, DFALP combined with suture button, and NSP. Then the above tests were repeated. The syndesmotic displacement and the strain of the tibia and fibula were recorded during the experiment. In most cases, the displacements and strains of the NSP group and the screw group were smaller than the suture button groups and the native (SBGAN) (p < .05), and the displacements and strains of the NSP group were also slightly smaller than the screw group in most cases, and there was no significant difference between the 2 groups. The NSP we developed has a fixed strength no less than the traditional syndesmotic screw fixation. This provides us a new idea for the treatment of distal tibiofibular syndesmosis injuries.

Tuning the Photophysical Properties of Symmetric Squarylium Dyes: Investigation on the Halogen Modulation Effects.

A series of symmetric squarylium dyes (SQDPA-X) with different halogen (X=F, Cl, Br, I) substituents have been developed. The photophysical properties could be facilely tuned by the halogen modulation effects. The strategy of incorporating different halogen substitutions into AIE active luminogens enables a facile approach for exploring new intriguing organic fluorescent dyes.

A Dual-Ion Organic Symmetric Battery Constructed from Phenazine-Based Artificial Bipolar Molecules.

Symmetric batteries received an increasing research interest in the past few years because of their simplified fabrication process and reduced manufacturing cost. In this study, we propose the first dual-ion organic symmetric cell based on a molecular anion of 4,4'-(phenazine-5,10-diyl)dibenzoate. The alkali salt of 4,4'-(phenazine-5,10-diyl)dibenzoate allows a facile transport of cations and large anions, and remains stable in both oxidized and reduced states. The large potential difference between phenazine and benzoate results in a high cell voltage of 2.5 V and an energy density of 127 Wh kg-1 at a current rate of 1 C. The introduction of bipolar organic materials may further consolidate the development of symmetric batteries that are fabricated from abundant elements and environmentally friendly materials.

Stable 2D Bisthienoacenes: Synthesis, Crystal Packing, and Photophysical Properties.

Two novel 2D bisthienoacenes with annulated thiophene units at different positions were developed. Both 1,2- and 1,4-addition of the α,ß-unsaturated ketone moieties lead to the major formation of four-fold alkylsilylethynyl substituted 2D heteroacenes (namely BTT-4TIPS and BTP-4TIPS). The photophysical, electrochemical properties, crystal packing structures, and charge carrier transport performances were investigated in detail.

Intermolecular Charge-Transfer Transition Emitter Showing Thermally Activated Delayed Fluorescence for Efficient Non-Doped OLEDs.

A novel molecular model of connecting electron-donating (D) and electron-withdrawing (A) moieties via a space-enough and conjugation-forbidden linkage (D-Spacer-A) is proposed to develop efficient non-doped thermally activated delayed fluorescence (TADF) emitters. 10-(4-(4-(4,6-diphenyl-1,3,5-triazin-2-yl) phenoxy) phenyl)-9,9-dimethyl-9,10-dihydroacridine (DMAC-o-TRZ) was designed and synthesized accordingly. As expected, it exhibits local excited properties in single-molecule state as D-Spacer-A molecular backbone strongly suppress the intramolecular charge-transfer (CT) transition. And intermolecular CT transition acted as the vital radiation channel for neat DMAC-o-TRZ film. As in return, the non-doped device exhibits a remarkable maximum external quantum efficiency (EQE) of 14.7 %. These results prove the feasibility of D-Spacer-A molecules to develop intermolecular CT transition TADF emitters for efficient non-doped OLEDs.

Precise Patterning of Organic Single Crystals via Capillary-Assisted Alternating-Electric Field.

Owing to the extraordinary properties, organic micro/nanocrystals are important building blocks for future low-cost and high-performance organic electronic devices. However, integrated device application of the organic micro/nanocrystals is hampered by the difficulty in high-throughput, high-precision patterning of the micro/nanocrystals. In this study, the authors demonstrate, for the first time, a facile capillary-assisted alternating-electric field method for the large-scale assembling and patterning of both 0D and 1D organic crystals. These crystals can be precisely patterned at the photolithography defined holes/channels at the substrate with the yield up to 95% in 1 mm2 . The mechanism of assembly kinetics is systematically studied by the electric field distribution simulation and experimental investigations. By using the strategy, various organic micro/nanocrystal patterns are obtained by simply altering the geometries of the photoresist patterns on substrates. Moreover, ultraviolet photodetectors based on the patterned Alq3 micro/nanocrystals exhibit visible-blind photoresponse with high sensitivity as well as excellent stability and reproducibility. This work paves the way toward high-integration, high-performance organic electronic, and optoelectronic devices from the organic micro/nanocrystals.

Z-Shaped Pentaleno-Acene Dimers with High Stability and Small Band Gap.

Acene-based materials have promising applications for organic electronics but the major constrain comes from their poor stability. Herein a new strategy to stabilize reactive acenes, by fusion of an anti-aromatic pentalene unit onto the zigzag edges of two acene units to form a Z-shaped acene dimer, is introduced. The Z-shaped acene dimers are extremely stable and show a small energy gap resulting from intramolecular donor-acceptor interactions. X-ray crystallographic analysis revealed their unique geometry and one-dimensional slip-stack columnar structure. Besides optical and electrochemical characterizations, solution-processed field-effect transistors were also fabricated.

Thienoacene-fused pentalenes: syntheses, structures, physical properties and applications for organic field-effect transistors.

Three soluble and stable thienoacene-fused pentalene derivatives (1-3) with different π-conjugation lengths were synthesized. X-ray crystallographic analysis and density functional theory (DFT) calculations revealed their unique geometric and electronic structures due to the interaction between the aromatic thienoacene units and antiaromatic pentalene moiety. As a result, they all possess a small energy gap and show amphoteric redox behaviour. Time dependent (TD) DFT calculations were used to explain their unique electronic absorption spectra. These new compounds exhibited good thermal stability and ordered packing in solid state and thus their applications in organic field-effect transistors (OFETs) were also investigated. The highest field-effect hole mobility of 0.016, 0.036 and 0.001 cm(2) V(-1) s(-1) was achieved for solution-processed thin films of 1-3, respectively.

Diagnostic efficacy of virtual organ computer-assisted analysis in measuring the volume ratio of subchorionic hematoma with serum progesterone.

BACKGROUND: Subchorionic hematoma (SCH) is a common complication in early pregnancy characterized by the accumulation of blood between the uterine wall and the chorionic membrane. SCH can lead to adverse pregnancy outcomes such as miscarriage, preterm birth, and other complications. Early detection and accurate assessment of SCH are crucial for appropriate management and improved pregnancy outcomes. AIM: To evaluate the diagnostic efficacy of virtual organ computer-assisted analysis (VOCAL) in measuring the volume ratio of SCH to gestational sac (GS) combined with serum progesterone on early pregnancy outcomes in patients with SCH. METHODS: A total of 153 patients with SCH in their first-trimester pregnancies between 6 and 11 wk were enrolled. All patients were followed up until a gestational age of 20 wk. The parameters of transvaginal two-dimensional ultrasound, including the circumference of SCH (Cs), surface area of SCH (Ss), circumference of GS (Cg), and surface area of GS (Sg), and the parameters of VOCAL with transvaginal three-dimensional ultrasound, including the three-dimensional volume of SCH (3DVs) and GS (3DVg), were recorded. The size of the SCH and its ratio to the GS size (Cs/Cg, Ss/Sg, 3DVs/3DVg) were recorded and compared. RESULTS: Compared with those in the normal pregnancy group, the adverse pregnancy group had higher Cs/Cg, Ss/Sg, and 3DVs/3DVg ratios (P < 0.05). When 3DVs/3DVg was 0.220, the highest predictive performance predicted adverse pregnancy outcomes, resulting in an AUC of 0.767, and the sensitivity, specificity were 70.2%, 75% respectively. VOCAL measuring 3DVs/3DVg combined with serum progesterone gave a diagnostic AUC of 0.824 for early pregnancy outcome in SCH patients, with a high sensitivity of 82.1% and a specificity of 72.1%, which showed a significant difference between AUC. CONCLUSION: VOCAL-measured 3DVs/3DVg effectively quantifies the severity of SCH, while combined serum progesterone better predicts adverse pregnancy outcomes.

Free-form and multi-physical metamaterials with forward conformality-assisted tracing.

Transformation theory, active control and inverse design have been mainstream in creating free-form metamaterials. However, existing frameworks cannot simultaneously satisfy the requirements of isotropic, passive and forward design. Here we propose a forward conformality-assisted tracing method to address the geometric and single-physical-field constraints of conformal transformation. Using a conformal mesh composed of orthogonal streamlines and isotherms (or isothermal surfaces), this method quasi-analytically produces free-form metamaterials using only isotropic media. The geometric nature of this approach allows for universal regulation of both dissipative thermal fields and non-dissipative electromagnetic fields. We experimentally demonstrate free-form thermal cloaking in both two and three dimensions. Additionally, the multi-physical functionalities of our method, including optical cloaking, bending and thermo-electric transparency, confirm its broad applicability. Our method features improvements in efficiency, accuracy and adaptability over previous approaches. This study provides an effective method for designing complex metamaterials with arbitrary shapes across various physical domains.

Dexamethasone induces developmental axon damage in the offspring hippocampus by activating miR-210-3p/miR-362-5p to target the aberrant expression of Sonic Hedgehog.

Given the extensive application of dexamethasone in both clinical settings and the livestock industry, human exposure to this drug can occur through various sources and pathways. Prior research has indicated that prenatal exposure to dexamethasone (PDE) heightens the risk of cognitive and emotional disorders in offspring. Axonal development impairment is a frequent pathological underpinning for neuronal dysfunction in these disorders, yet it remains unclear if it plays a role in the neural damage induced by PDE in the offspring. Through RNA-seq and bioinformatics analysis, we found that various signaling pathways related to nervous system development, including axonal development, were altered in the hippocampus of PDE offspring. Among them, the Sonic Hedgehog (SHH) signaling pathway was the most significantly altered and crucial for axonal development. By using miRNA-seq and targeting miRNAs and glucocorticoid receptor (GR) expression, we identified miR-210-3p and miR-362-5p, which can target and suppress SHH expression. Their abnormal high expression was associated with GR activation in PDE fetal rats. Further testing of PDE offspring rats and infant peripheral blood samples exposed to dexamethasone in utero showed that SHH expression was significantly decreased in peripheral blood mononuclear cells (PBMCs) and was positively correlated with SHH expression in the hippocampus and the expression of the axonal development marker growth-associated protein-43. In summary, PDE-induced hippocampal GR-miR-210-3p/miR-362-5p-SHH signaling axis changes lead to axonal developmental damage. SHH expression in PBMCs may reflect axonal developmental damage in PDE offspring and could serve as a warning marker for fetal axonal developmental damage.

Bifacial DNA origami-directed discrete, three-dimensional, anisotropic plasmonic nanoarchitectures with tailored optical chirality.

Discrete three-dimensional (3D) plasmonic nanoarchitectures with well-defined spatial configuration and geometry have aroused increasing interest, as new optical properties may originate from plasmon resonance coupling within the nanoarchitectures. Although spherical building blocks have been successfully employed in constructing 3D plasmonic nanoarchitectures because their isotropic nature facilitates unoriented localization, it still remains challenging to assemble anisotropic building blocks into discrete and rationally tailored 3D plasmonic nanoarchitectures. Here we report the first example of discrete 3D anisotropic gold nanorod (AuNR) dimer nanoarchitectures formed using bifacial DNA origami as a template, in which the 3D spatial configuration is precisely tuned by rationally shifting the location of AuNRs on the origami template. A distinct plasmonic chiral response was experimentally observed from the discrete 3D AuNR dimer nanoarchitectures and appeared in a spatial-configuration-dependent manner. This study represents great progress in the fabrication of 3D plasmonic nanoarchitectures with tailored optical chirality.