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The critical dimension of semiconductor devices is approaching the single-nm regime, and a variety of practical devices of this scale are targeted for production. Planar structures of nano-devices are still the center of fabrication techniques, which limit further integration of devices into a chip. Extension into 3D space is a promising strategy for future; however, the surface interaction in 3D nanospace make it hard to integrate nanostructures with ultrahigh aspect ratios. Here we report a unique technique using high-energy charged particles to produce free-standing 1D organic nanostructures with high aspect ratios over 100 and controlled number density. Along the straight trajectory of particles penetrating the films of various sublimable organic molecules, 1D nanowires were formed with approximately 10~15 nm thickness and controlled length. An all-dry process was developed to isolate the nanowires, and planar or coaxial heterojunction structures were built into the nanowires. Electrical and structural functions of the developed standing nanowire arrays were investigated, demonstrating the potential of the present ultrathin organic nanowire systems. Extension of nanostructure fabrication in the single-nm regime is a promising but fabrication of nanostructures with high aspect ratios remains challenging. Here, the authors use high energy charged particles to produce free-standing 1D organic nanostructures with extremely high aspect ratios and controlled number density.

Radicals arranged in a two-dimensional (2D) hexagonal network can offer various exotic magnetic, electronic, and optical properties that find application in electronics/spintronics. However, direct synthesis remains challenging due to the scarcity of stable, symmetry-matched radical building blocks. Here, we report the bottom-up synthesis of hexagonal 2D radical covalent organic frameworks (RCOFs) with unpaired electrons at the nodes of the frameworks. A planar verdazyl radical amine (V-NH 2 ) undergoes Schiff-base condensation with aldehydes to afford highly crystalline hexagonal RCOFs (VTPT and VPMT). The spin density was precisely controlled through the selection of building blocks with modulated spin-spin distances. The EPR and SQUID measurements confirmed a high spin concentration with antiferromagnetic interactions at low temperature, which is further tuned by interlayer interactions. Thin films of VTPT exhibited preferential in-plane orientation with enhanced photoconductivity, attributed to improved π-conjugation. These findings establish a direct route to RCOFs and underscore their potential as pseudo 1-dimensional antiferromagnetic materials. The direct synthesis of 2D radical covalent organic frameworks (RCOFs) from radical precursors remains a significant challenge. Here, the authors report the bottom up synthesis of hexagonal 2D RCOFs in which radical units are retained within the framework backbone.

An organic nanowire fabrication technique, i.e., single‐particle‐triggered linear polymerization, which yields nanowires consisting of a wide range of organic molecules with perfectly controlled sizes, is developed via chemical reactions induced by a high‐energy charged particle. A freestanding purely organic nanowire array (ONA) structure is fabricated to maximize the surface area with the designed surface affinity for analyte molecules. The ONA is demonstrated as an effective sensing platform for Raman spectroscopy with a high enough sensitivity against a series of analytes including rhodamine, crystal violet, methylene blue, neutral red, methyl orange, as well as oligopeptides. The designed electron transfer reactions between the analytes and nanowires provide Raman signal enhancement factors of up to 108 with the detection limit of the analytes as 10−9 M for the rhodamine, indicating the viability of these ONAs as a novel class of metal‐free Raman sensing probes. A freestanding purely organic nanowire array (ONA) structure is fabricated to maximize the surface area with the designed surface affinity for analyte molecules. The designed electron transfer reactions between the analytes and nanowires provide Raman signal enhancement factors of up to 108 with the detection limit of the analytes as 10−9 M for the analytes, indicating the viability of these ONAs as a novel class of metal‐free Raman sensing probes.

Stereochemistry is a potent way to direct the molecular packing in condensed phases. Here, we synthesized the enantiopure, racemic, and achiral isomers of p‐type small molecule, that is, indacenodithieno[3,2‐b]thiophene, to understand the impact of stereochemistry on molecular packing and solid‐state properties. In the solution state, the optical properties remain nearly identical among the isomers; however, a significant difference was observed in the condensed phase. X‐ray diffraction pattern revealed enantiopure isomers were more tightly packed and exhibited strong π‐stacking relative to their racemic and achiral counterparts. Two‐dimensional arrangement of the stacked enantiopure isomers gives more dense‐packed crystalline phases than an achiral analog, which is unusual anti‐Wallach type condensed phases. The enantiopure one exhibited two times higher photoconductivity than its achiral or racemic analogues, as well as showing high electron spin polarizability (∼75%) with electrical current throughput (100 nA). The result highlights the role of stereochemistry as a key strategy to direct the condensed phase packing and properties in conjugated crystals. Chirality dictates solid‐state behavior in ladder‐type indacenodithieno[3,2‐b]thiophene semiconductors. Enantiopure RR/SS‐ITMPEA forms more ordered packing and larger crystallites than racemic or achiral analogues, leading to nearly double photoconductivity as revealed by flash photolysis time‐resolved microwave conductivity.

Blue laser annealing can be used to obtain a high-mobility thin-film transistor (TFT) through a laser annealing (i.e., LTPS: low-temperature Poly-Si) process. However, the laser annealing process’s low productivity (as well as high cost) is an issue because the high output power of blue lasers still needs to be addressed. Therefore, productivity can be improved if blue laser energy is efficiently supplied during the laser annealing process using a continuous wave laser instead of a conventional pulsed excimer laser. We developed a blue laser light source (440 ± 10 nm) using the wavelength beam combining (WBC) method, which can achieve a laser power density of 73.7 kW/cm2. In this semiconductor laser, when the power was increased s by 2.9 times, the laser scanning speed was increased by 5.0 times, achieving twice the productivity of conventional lasers. After laser annealing, the size of the crystal grains varied between 2 and 15 μm, resulting in a crystallization rate of 100% by Raman scattering rsult and low resistivity of 0.04 Ωcm. This increase in production capacity is not an arithmetic increase with increased power but a geometric production progression.

Background/Objectives: The translation of in vitro biomaterial evaluations into successful clinical applications often fails due to discrepancies with in vivo results. Previously, we demonstrated that differences in culture medium conditions influence the bone formation process. This study aimed to investigate the influence of culture media on gene expression during calcification induction in osteoblasts. Methods: Using MC3T3-E1 cells cultured in α Minimum Essential Medium without L-ascorbic acid (αMEM(−)) and Dulbecco’s Modified Eagle Medium (DMEM), we screened gene expression profiles through microarray analysis and validated key findings with quantitative PCR. Additionally, we compared these gene expression patterns with those in primary osteoblasts (POBs) cultured under the same medium conditions. Results: The results revealed distinct gene expression profiles in MC3T3-E1 cells depending on the culture medium, while POBs exhibited minimal differences between media, except for the gene Alpl. In αMEM(−), Alpl expression in POBs was significantly increased approximately 4-fold via calcification stimulation (p < 0.0001). POBs cultured in DMEM showed calcification appearance differing from the αMEM(−) condition, even though no significant increase in Alpl expression via calcification stimulation was observed. Conclusions: Differences in media appear to remarkably impact osteoblast gene expression and mineralization. These findings may help improve biomaterial evaluation when transitioning from in vitro assessments to in vivo evaluations. Moreover, our results suggest the possibility that gene expression differences observed in MC3T3-E1 cells reflect the diverse bone formation processes in vivo. Focusing on these genes could facilitate the development of screening methods for bone formation, supporting future clinical applications in orthopedics.

The progress in artificial bone research is crucial for addressing fractures and bone defects in the aging population. However, challenges persist in terms of biocompatibility and structural complexity. Nanotechnology provides a promising avenue by which to overcome these challenges, with nano-ferrite particles (NFPs) exhibiting superparamagnetic properties. The ability to control cell positioning using a magnetic field opens up new possibilities for customizing artificial bones with specific shapes. This study explores the biological effects of NFPs on osteoblast-like cell lines (MC3T3-E1), including key analyses, such as cell viability, cellular uptake of NFPs, calcification processes, cell migration under external magnetic field conditions, and three-dimensional modeling. The results indicate that the impact of NFPs on cell proliferation is negligible. Fluorescence and transmission electron microscopy validated the cellular uptake of NFPs, demonstrating the potential for precise cell positioning through an external magnetic field. Under calcification-inducing conditions, the cells exhibited sustained calcification ability even in the presence of NFPs. The cell movement analysis observed the controlled movement of NFP-absorbing cells under an external magnetic field. Applying a magnetic field along the z-axis induced the three-dimensional shaping of cells incorporating NFPs, resulting in well-arranged z-axis directional patterns. In this study, NFPs demonstrated excellent biocompatibility and controllability under an external magnetic field, laying the foundation for innovative treatment strategies for customizing artificial bones.

BackgroundSecondary mitral regurgitation (MR) remains a challenging problem in the diagnosis and treatment of patients with heart failure. Although it is well known that secondary MR is dynamic, the impact of the severity of MR during exercise on long-term outcome has not been fully evaluated. The aim of the present study was to investigate the prognostic value of exercise stress echocardiography (ESE) in patients with secondary MR.MethodsThis prospective study included 118 consecutive patients with secondary MR and left ventricular dysfunction (mean ejection fraction at rest: 38 ± 14%) who underwent semi-supine ESE. Their major cardiovascular events (MACE) including cardiac death were followed up for a median of 41.7 (range: 6–128) months.ResultsMR significantly increased from rest to exercise (effective regurgitant orifice: 0.18 ± 0.09 vs. 0.25 ± 0.12 cm2, P < 0.001). The prevalence of severe MR was higher during exercise than those at rest (37% vs. 56%, P < 0.001). During follow-up, MACE occurred in 49 patients (41.5%) including 12 cardiac deaths. Cox proportional-hazard multivariate analysis revealed that older age and MR severity during exercise were significantly associated with increased risk of MACE (hazard ratio: 1.04 and 8.4, respectively, both P < 0.05).ConclusionsESE provides prognostic information in patients with secondary MR that is useful for predicting long-term outcome.

BackgroundSurgical timing of chronic aortic regurgitation (AR) remains a matter of debate because of limited data. This study assessed the prognostic value of exercise echocardiography in asymptomatic AR.MethodsThis prospective study included 60 consecutive asymptomatic patients with isolated moderate or severe AR (mean regurgitant volume 56.7 ± 11.8 ml) and preserved ejection fraction who underwent exercise echocardiography. The clinical outcomes were defined by the presence of major adverse cardiovascular events (MACE) and the indication for aortic valve replacement (AVR) with class I or IIa classification in the current guidelines.ResultsDuring the average follow-up of 731 days, 12 patients suffered from the clinical events, including two patients developing MACE (3%) and ten patients indicating for AVR (17%). No difference in left ventricular (LV) ejection fraction at rest was found between the patients with and without the clinical events. The indexed LV diameters and LV volumes were significantly dilated in the patients with the clinical events. The Cox proportional hazards regression analysis resulted that the exercise LV end-systolic volume index (LVESVi) was significantly associated with the clinical outcomes [hazard ratio, 1.116; 95% CI (1.032–1.205); p = 0.006]. The Kaplan–Meier analysis showed that exercise LVESVi was clearly stratified the event-free survival.ConclusionsExercise LVESVi might be an independent predictor of prognosis in patients with asymptomatic moderate or severe AR.

The serum hyaluronate (HA) level reflects sinusoidal endothelial cell function correlated with liver function. We have reviewed multiple liver function indicators from 37 patients who underwent hepatectomy for various liver diseases. The serum HA level was well correlated with the indocyanine green retention rate at 15 minutes (ICGR15), lectin‐cholesterol (LCAT), hepatocyte growth factor (HGF), liver uptake ratio of technetium‐99m galactosyl human serum albumin (99mTc‐GSA) at 15 minutes (HH15), prealbumin, and hepatic uptake ratio of 99mTc‐GSA at 15 minutes (LHL15). In addition, the model for end‐stage liver disease (MELD) score at 7 days after operation was well correlated with serum HA, ICGR15, HH15, and LHL15. In patients who showed serum an HA level of = 100 ng/ml before hepatectomy, the MELD score had significantly deteriorated by 7 days after hepatectomy. Of the 20 patients who showed a serum HA level < 100 ng/ml before hepatectomy, 11 had high serum HA after hepatectomy. The bilirubin level 7 days after operation in this group was much higher than that for patients who maintained a serum HA level < 100 ng/ml after hepatectomy. In addition, the serum HGF level before hepatectomy in this group was significantly lower. We concluded that the serum HA level is a reliable indicator when evaluating liver function and predicting liver dysfunction after hepatectomy. Furthermore, patients with a significantly low HGF level who have a normal HA level are susceptible to liver dysfunction after hepatectomy.