ABSTRACT
The efficient dispersion of single-walled carbon nanotubes (SWCNTs) has been the subject of extensive research over the past decade. Despite these efforts, achieving individually dispersed SWCNTs at high concentrations remains challenging. In this study, we address the limitations associated with conventional methods, such as defect formation, excessive surfactant use, and the use of corrosive solvents. Our novel dispersion method utilizes the spontaneous charging of SWCNTs in a solvated electron system created by dissolving potassium in hexamethyl phosphoramide (HMPA). The resulting charged SWCNTs (c-SWCNTs) can be directly dispersed in the charging medium using only magnetic stirring, leading to defect-free c-SWCNT dispersions with high concentrations of up to 20 mg/mL. The successful dispersion of individual c-SWCNT strands is confirmed by their liquid-crystalline behavior. Importantly, the dispersion medium for c-SWCNTs exhibits no reactivity with metals, polymers, or other organic solvents. This versatility enables a wide range of applications, including electrically conductive free-standing films produced via conventional blade coating, wet-spun fibers, membrane electrodes, thermal composites, and core-shell hybrid microparticles.
ABSTRACT
Criteria Based Content Analysis (CBCA) is a forensic tool that analyzes victim statements. It involves the categorization of victims' statements into 19 distinct criteria classifications, playing a crucial role in evaluating the authenticity of testimonies by discerning whether they are rooted in genuine experiences or fabricated accounts. The exclusion of subjective opinions becomes imperative to assess statements through this forensic tool objectively. This study proposes developing an objective classification model for CBCA-based statement analysis using natural language processing techniques. Nevertheless, achieving optimal classification performance proves challenging due to imbalances in data distribution among the various criterion classifications. To enhance the accuracy and reliability of the classification model, this research employs data augmentation techniques and dual contrastive learning methods for fine-tuning the RoBERTa language model. Furthermore, model-based optimization techniques are also applied to identify augmented hyper-parameters and maximize the model's classification performance. The study's findings, including an 8.5% improvement in macro F1 score compared to human classification results, a 24% improvement in macro F1 score, and a 13% improvement in accuracy compared to previous human classification results, suggest that the proposed model is highly effective in reducing the influence of human subjectivity in statement analysis. The proposed model has significant implications for legal proceedings and criminal investigations, as it can provide a more objective and reliable method for evaluating the credibility of victim statements. Reducing human subjectivity in the statement analysis process can increase the accuracy of verdicts and help ensure that justice is served.
ABSTRACT
The demand for high-resolution and large-area imaging systems for non-destructive wafer inspection has grown owing to the increasing complexity and extremely fine nature of semiconductor processes. Several studies have focused on developing high-resolution imaging systems; however, they were limited by the tradeoff between image resolution and field of view. Hence, computational imaging has arisen as an alternative method to conventional optical imaging, aimed at enhancing the aforementioned parameters. This study proposes a method for improving the resolution and field of view of an image in a lens-less reflection-type system. Our method was verified by computationally restoring the final image from diffraction images measured at various illumination positions using a visible light source. We introduced speckle illumination to expand the numerical aperture of the entire system, simultaneously improving image resolution and field of view. The image reconstruction process was accelerated by employing a convolutional neural network. Using the reconstructed phase images, we implemented high-resolution topography and demonstrated its applicability in wafer surface inspection. Furthermore, we demonstrated an ideal diffraction-limited spatial resolution of 1.7 µm over a field of view of 1.8 × 1.8 mm2 for the topographic imaging of targets with various surface roughness. The proposed approach is suitable for applications that simultaneously require high throughput and resolution, such as wafer-wide integrated metrology, owing to its compact design, cost-effectiveness, and mechanical robustness.
ABSTRACT
Lung cancer carries one of the highest mortality rates among all cancers. It is often diagnosed at more advanced stages with limited treatment options compared to other malignancies. This study focuses on calnexin as a potential biomarker for diagnosis and treatment of lung cancer. Calnexin, a molecular chaperone integral to N-linked glycoprotein synthesis, has shown some associations with cancer. However, targeted therapeutic or diagnostic methods using calnexin have been proposed. Through 1D-LCMSMS, we identified calnexin as a biomarker for lung cancer and substantiated its expression in human lung cancer cell membranes using Western blotting, flow cytometry, and immunocytochemistry. Anti-calnexin antibodies exhibited complement-dependent cytotoxicity to lung cancer cell lines, resulting in a notable reduction in tumor growth in a subcutaneous xenograft model. Additionally, we verified the feasibility of labeling tumors through in vivo imaging using antibodies against calnexin. Furthermore, exosomal detection of calnexin suggested the potential utility of liquid biopsy for diagnostic purposes. In conclusion, this study establishes calnexin as a promising target for antibody-based lung cancer diagnosis and therapy, unlocking novel avenues for early detection and treatment. [BMB Reports 2024; 57(3): 155-160].
Subject(s)
Lung Neoplasms , Humans , Calnexin/metabolism , Lung Neoplasms/diagnosis , Lung Neoplasms/drug therapy , Calcium-Binding Proteins/metabolism , Molecular Chaperones/metabolism , BiomarkersABSTRACT
In this study, the intrinsic brittleness of poly(lactic acid) (PLA) was overcome by chemical modification using ethyl acetate-extracted lignin (EL) via cationic ring-opening polymerization (CROP). The CROP was conducted to promote homopolymerization under starvation of the initiator (oxyrane). This method resulted in the formation of lignin-based polyether (LPE). LPE exhibited enhanced interfacial compatibility with nonpolar and hydrophobic PLA owing to the fewer hydrophilic hydroxyl groups and a long polyether chain. In addition, because of the UV-protecting and radical-scavenging abilities of lignin, LPE/PLA exhibited multifunctional properties, resulting in improved chemical properties compared with the neat PLA film. Notably, one of the LPE/PLA films (EL_MCF) exhibited excellent elongation at break of 297.7 % and toughness of 39.92 MJ/m3. Furthermore, the EL_MCF film showed superior UV-protective properties of 99.52 % in UVA and 88.95 % in UVB ranges, both significantly higher than those of the PLA film, without sacrificing significant transparency in 515 nm. In addition, the radical scavenging activity improved after adding LPE to the PLA film. These results suggest that LPEs can be used as plasticizing additives in LPE/PLA composite films, offering improved physicochemical properties.
Subject(s)
Lignin , Polyesters , Lignin/chemistry , Polymerization , Polyesters/chemistryABSTRACT
In this work, we initially prepared layered lithium titanate (Li2TiO3) using a solid-state reaction. Then Li+ of Li2TiO3 were acid-eluded with Hydrochloric acid to obtain hydrated titanium oxide (H2TiO3). Different weight percentages (50%, 60%, 70%, 80%, and 90%) of the as-prepared H2TiO3 were deposited on a conductive reduced graphene oxide (rGO) matrix to obtain a series of rGO/ H2TiO3 composites. Of the prepared composites, rGO/H2TiO3-60% showed excellent current density, high specific capacitance, and rapid ion diffusion. An asymmetric MCDI (membrane capacitive deionization) cell fabricated with activated carbon as the anode and rGO/H2TiO3-60% as the cathode displayed outstanding Li+ electrosorption capacity (13.67 mg g-1) with a mean removal rate of 0.40 mg g-1 min-1 in a 10 mM LiCl aqueous solution at 1.8 V. More importantly, the rGO/H2TiO3-60% composite electrode exhibited exceptional Li+ selectivity, superior cyclic stability up to 100,000 s, and a Li+ sorption capacity retention of 96.32% after 50 adsorption/desorption cycles. The excellent Li+ extraction obtained by MCDI using the rGO/H2TiO3-60% negative electrode was putatively attributed to: (i) ion exchange between Li+ and H+ of H2TiO3; (ii) the presence of narrow lattice spaces in H2TiO3 suitable for selective Li+ capture; (iii) capture of Li+ by isolated and hydrogen-bonded hydroxyl groups of H2TiO3; and (iv) enhanced interfacial contact and transfer of large numbers of Li+ ions from the electrolyte to H2TiO3 achieved by compositing H2TiO3 with a highly conductive rGO matrix.
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BACKGROUND: Little is known about the self-perceived level of disability of stroke survivors in the community. We aimed to characterise Health-related quality of life (HRQoL) 1 year after stroke and investigate how sociodemographic and stroke-related factors and medical adherence explain the self-perceived level of disability in a Korean stroke population. METHODS: This was a multicentre cross-sectional study. A total of 382 ischaemic stroke survivors at 1 year after onset from 11 university hospitals underwent a one-session assessment, including socioeconomic variables, the modified Rankin Scale (mRS), various neurological sequelae, the Morisky, Green and Levin-Medication Adherence Questionnaire (MGL), and the World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0) 36-items. The relationship between disability and different variables was analysed using ordinal logistic regression. RESULTS: The prevalence of disability based on global WHODAS 2.0 was 62.6% (mild, 41.6%; moderate, 16.0%; severe, 5.0%). The prevalence of severe disability was higher in participation in society (16.8%) and getting around (11.8%) than in other domains. Low MGL- motivation was the only factor determining a significant association between all six domains of disability after adjustment. Different predictors for specific domains were age, mRS, dysarthria, trouble seeing, cognition problems, and MGL-motivation for understanding and communicating; age, recurrent stroke, mRS, hemiplegia, facial palsy, general weakness, and MGL-motivation for getting around; age, education, mRS, hemiplegia, and MGL-motivation for self-care; education, recurrent stroke, hemiplegia, dysarthria, and MGL-motivation for getting along with people; age, education, income, mRS, hemiplegia, dysarthria, MGL-knowledge, and MGL-motivation for life activities; living without a spouse, mRS, hemiplegia, dysarthria, trouble seeing, cognition problems, general weakness, and MGL-motivation for participation in society. CONCLUSIONS: Self-perceived disability according to the WHODAS 2.0 at 1 year after stroke was highly prevalent. Each disability domain showed a different prevalence and associated factors. Interventions promoting medical adherence to motivation seemed to help achieve high HRQoL in all domains.
Subject(s)
Brain Ischemia , Stroke , Humans , Stroke/epidemiology , Activities of Daily Living , Cross-Sectional Studies , Quality of Life , Dysarthria , Hemiplegia , Republic of Korea/epidemiology , Disability EvaluationABSTRACT
Anionic dyes are one of the most serious contaminants in water as these molecules are known to be toxic to many living organisms. Herein, we report the development of functionalized polyvinylidene fluoride membranes modified with chitosan-coated iron oxide nanomaterials (Fe-PVDF) for the efficient treatment of anionic dye-contaminated water. Aqueous solutions of anionic dyes could be captured rapidly by passing through the functionalized membrane under reduced pressure. Under neutral conditions, Fe-PVDF showed a maximum removal capacity of 74.6 mg/g for Evans blue (EB) through the adsorption process. In addition, the adsorption capacity was significantly enhanced up to 434.78 mg/g under acidic conditions. The adsorption process for EB matched well with the Langmuir model, indicating monolayer adsorption of the dye to the membrane surface. Moreover, Fe-PVDF can be reusable by a simple washing step in an alkaline solution, and thus, the composite membrane was applied several times without a significant decrease in its adsorption performance. The same composite membrane was further applied to the removal of five other different anionic dyes with high efficiencies. The adsorption mechanism can be explained by the electrostatic interaction between the positively charged chitosan and the negatively charged dye as well as the affinity of the sulfate groups in dye molecules for the surface of the iron oxide nanoparticles. The easy preparation and rapid decolorization procedures make this composite membrane suitable for efficient water treatment.
ABSTRACT
Chromium is a toxic and carcinogenic heavy metal that originates from various human activities. Therefore, the effective removal of chromium from aqueous solutions is an extremely important global challenge. Herein, we report a chitosan-coated iron oxide nanoparticle immobilized hydrophilic poly(vinylidene) fluoride membrane (Chi@Fe2O3-PVDF) which can potentially be used for efficient removal of hexavalent chromium(VI) by a simple filtration process. Membrane filtration is an easy and efficient method for treating large volumes of water in a short duration. The adsorption experiments were conducted by batch and continuous in-flow systems. The experimental data showed rapid capture of hexavalent chromium (Cr(VI)) which can be explained by the pseudo-second-order kinetic and Langmuir isotherm model. The nanocomposite membrane exhibited high adsorption capacity for Cr(VI) (14.451 mg/g in batch system, 14.104 mg/g in continuous in-flow system). Moreover, its removal efficiency was not changed significantly in the presence of several competing ions, i.e., Cl-, NO3-, SO42-, and PO43-. Consequently, the Chi@Fe2O3-PVDF-based filtration process is expected to show a promising direction and be developed as a practical method for wastewater treatment.
ABSTRACT
The deflection of charged particles is an intuitive way to visualize an electromagnetic oscillation of coherent light. Here, we present a real-time ultrafast oscilloscope for time-frozen visualization of a terahertz (THz) optical wave by probing light-driven motion of relativistic electrons. We found the unique condition of subwavelength metal slit waveguide for preserving the distortion-free optical waveform during its propagation. Momentary stamping of the wave, transversely travelling inside a metal slit, on an ultrashort wide electron bunch enables the single-shot recording of an ultrafast optical waveform. As a proof-of-concept experiment, we successfully demonstrated to capture the entire field oscillation of a THz pulse with a sampling rate of 75.7 TS/s. Owing to the use of transversely-wide and longitudinally-short electron bunch and transversely travelling wave, the proposed "single-shot oscilloscope" will open up new avenue for developing the real-time petahertz (PHz) metrology.
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The experimental observation of femtosecond dynamics in atoms and molecules by stroboscopic technologies utilizing x ray or electron flashes has attracted much attention and has rapidly developed. We propose a feasible ultrafast electron diffraction (UED) technology with high brightness and a sub-10 fs temporal resolution. We previously demonstrated a UED system with an overall temporal resolution of 31 fs by using an RF photoelectron gun and a 90° achromatic bending structure. This UED structure enabled a bunch duration of 25 fs and a low timing jitter of less than 10 fs while maintaining a high bunch charge of 0.6 pC. In this paper, we demonstrate a simple way to further compress the electron bunch duration to sub-10 fs based on installing an energy filter in the dispersion section of the achromatic bend. The energy filter removes the electrons belonging to nonlinear parts of the phase space. Through numerical simulations, we demonstrate that the electron bunches can be compressed, at the sample position, to a 6.2 fs (rms) duration for a 100 fC charge. This result suggests that the energy filtering approach is more viable and effective than complicated beam-shaping techniques that commonly handle the nonlinear distribution of the electron beam. Furthermore, a gas-filled hollow core fiber compressor and a Ti:sapphire amplifier are used to implement pump laser pulses of less than 5 fs (rms). Thus, we could present the full simulation results of a sub-10 fs UED, and we believe that it will be one of the technical prototypes to challenge the sub-fs time resolution.
ABSTRACT
Higher repetition-rate optical pulse trains have been desired for various applications such as high-bit-rate optical communication, photonic analogue-to-digital conversion, and multi-photon imaging. Generation of multi GHz and higher repetition-rate optical pulse trains directly from mode-locked oscillators is often challenging. As an alternative, harmonic injection locking can be applied for extra-cavity repetition-rate multiplication (RRM). Here we have investigated the operation conditions and achievable performances of all-fibre, highly tunable harmonic injection locking-based pulse RRM. We show that, with slight tuning of slave laser length, highly tunable RRM is possible from a multiplication factor of 2 to >100. The resulting maximum SMSR is 41 dB when multiplied by a factor of two. We further characterize the noise properties of the multiplied signal in terms of phase noise and relative intensity noise. The resulting absolute rms timing jitter of the multiplied signal is in the range of 20 fs to 60 fs (10 kHz-1MHz) for different multiplication factors. With its high tunability, simple and robust all-fibre implementation, and low excess noise, the demonstrated RRM system may find diverse applications in microwave photonics, optical communications, photonic analogue-to-digital conversion, and clock distribution networks.
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Polydeoxyribonucleotide (PDRN) is safe and effective in wound healing, cellular growth, synthesis of extracellular matrix protein, and inflammation reduction via activation of adenosine A2 receptors. We report a 28-year-old male patient treated with PDRN injections for chronic non-healing wound refractory to negative pressure wound therapy, skin graft, or growth factors. Three injections of PDRN were administered at the wound site into the anterior and medial sides of the left stump on the 1st, 4th, and 9th days of hospitalization. The PDRN ameliorated wound healing by enhancing cell growth, tissue repair, and angiogenesis. PDRN application represents a potential treatment for non-healing wounds obviating the need for additional therapies, and hospitalization, as well as improve patient's activities of daily living.
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Ultrafast electron-based coherent radiation sources, such as free-electron lasers (FELs), ultrafast electron diffraction (UED) and Thomson-scattering sources, are becoming more important sources in today's ultrafast science. Photocathode laser is an indispensable common subsystem in these sources that generates ultrafast electron pulses. To fully exploit the potentials of these sources, especially for pump-probe experiments, it is important to achieve high-precision synchronization between the photocathode laser and radio-frequency (RF) sources that manipulate electron pulses. So far, most of precision laser-RF synchronization has been achieved by using specially designed low-noise Er-fibre lasers at telecommunication wavelength. Here we show a modular method that achieves long-term (>1 day) stable 10-fs-level synchronization between a commercial 79.33-MHz Ti:sapphire laser oscillator and an S-band (2.856-GHz) RF oscillator. This is an important first step toward a photocathode laser-based femtosecond RF timing and synchronization system that is suitable for various small- to mid-scale ultrafast X-ray and electron sources.
ABSTRACT
Timing jitter is one of the most important properties of femtosecond mode-locked lasers and optical frequency combs. Accurate measurement of timing jitter power spectral density (PSD) is a critical prerequisite for optimizing overall noise performance and further advancing comb applications both in the time and frequency domains. Commonly used jitter measurement methods require a reference mode-locked laser with timing jitter similar to or lower than that of the laser-under-test, which is a demanding requirement for many laser laboratories, and/or have limited measurement resolution. Here we show a high-resolution and reference-source-free measurement method of timing jitter spectra of optical frequency combs using an optical fibre delay line and optical carrier interference. The demonstrated method works well for both mode-locked oscillators and supercontinua, with 2 × 10-9 fs2/Hz (equivalent to -174 dBc/Hz at 10-GHz carrier frequency) measurement noise floor. The demonstrated method can serve as a simple and powerful characterization tool for timing jitter PSDs of various comb sources including mode-locked oscillators, supercontinua and recently emerging Kerr-frequency combs; the jitter measurement results enabled by our method will provide new insights for understanding and optimizing timing noise in such comb sources.
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Cytokeratin 17 (CK17), a basal/myoepithelial cell keratin, is a poor prognostic marker for cancers of organs such as the stomach, ovary, and breast as well as a useful diagnostic marker for pancreatobiliary adenocarcinoma. However, its expression pattern and prognostic significance have not been studied in gallbladder adenocarcinoma. We constructed a tissue microarray from samples from 82 consecutive patients with gallbladder adenocarcinoma treated by cholecystectomy at the Kangbuk Samsung Hospital from 2000 to 2011. CK17 expression was examined by immunohistochemistry and correlated with clinicopathologic prognostic factors. CK17 stained the cytoplasm of tumor cells and immunohistochemical interpretation was possible in 77 cases. Among these, 41 (53.2%) were considered positive using a 5% cutoff determined by a receiver operating characteristic curve (area under the curve=0.656, P=0.021). CK17 expression was associated with poor tumor differentiation (P<0.001), high pT stage (P<0.001), presence of distant metastasis (P=0.036), and low disease-specific survival rate (P<0.001). These results indicate that CK17 can be used as a marker for poor prognosis for gallbladder adenocarcinoma.
Subject(s)
Adenocarcinoma/diagnosis , Biomarkers, Tumor/standards , Gallbladder Neoplasms/diagnosis , Gene Expression Regulation, Neoplastic , Keratin-17/genetics , Adenocarcinoma/genetics , Adenocarcinoma/physiopathology , Female , Gallbladder Neoplasms/genetics , Gallbladder Neoplasms/physiopathology , Gene Expression Profiling , Humans , Immunohistochemistry , Keratin-17/metabolism , Male , Prognosis , Retrospective Studies , Tissue Array AnalysisABSTRACT
We characterize and analyze the timing jitter of normal-dispersion mode-locked Er-fiber lasers with intra-cavity filtering. The timing jitter of Er-fiber lasers with 9-nm bandpass filters operating at + 0.0084 ps(2) is measured to be 3.46 fs (rms) when integrated from 10 kHz to 10 MHz offset frequency, which is similar to the jitter level of typical stretched-pulse or soliton Er-fiber lasers. The numerical simulation based on split-step Fourier transform method shows that the measured high-frequency jitter is quantum noise-limited performance. We also develop an analytical model for filtered normal-dispersion fiber lasers by modifying the well-established noise model of stretched-pulse fiber lasers. The analytical modeling reveals that the jitter performance is improved mostly by reducing the chirp parameter by intra-cavity filtering. Both numerical simulation and analytical model fit fairly well with the measured timing jitter result.
ABSTRACT
[Purpose] This study was conducted to find out the effect of arm swing during treadmill training on the gait of stroke patients. [Subjects and Methods] This study subjects were 20 stroke subjects patients who were randomly assigned to either the experimental group (EG) or the control group (CG), 10 subjects in each group. Therapists induced arm swing of affected side of EG subjects using Nordic poles, while subjects in CG had the affected arm restricted to prevent arm swing. Training was performed for 30 minutes, 3 times a week for 4 weeks. The timed up and go test (TUG), the dynamic gait index (DGI) and the 6-minute walk test (6MWT) were assessed before and after the training. [Results] After the training, there were no significant differences in the TUG times of EG and CG. There were significant differences in the DGI and the 6-minute walking distance of EG, but not of CG. There were also significant differences in the improvements of the DGI and the 6-minute walking distance between the groups. [Conclusion] Arm swing training had a positive effect on patients' gait ability. Further studies are required to generalize the results of this study.
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[Purpose] The aim of this study was to examine the initial effects of chest expansion resistance exercise (CERE) applied to chronic stroke patients on their pulmonary functions, chest expansion, and functional gait ability. [Subjects] Forty chronic stroke patients without any respiration-related rehabilitation program experience (21 men and 19 women; times elapsed since occurrence of stroke: 21.8 ± 5.3 months) were randomly and equally allocated to a CERE group (experimental group) and a control group. [Methods] An ordinary stroke rehabilitation program was performed on the subjects. While the experimental group received a CERE intervention, the control group performed passive range of motion exercise with automatic instruments. [Results] The CERE group's chest expansion significantly increased after the intervention, whereas the control group did not see any significant difference. As regards VC (vital capacity), FVC (forced vital capacity), and FEV1 (forced expiratory volume in one second), there were no significant changes in either the CERE or control group. In the 10MTWT (10-meter timed walking test), there were no significant changes in either group, but in the 6MWT (6-minute walk test), while there were no significant differences in the control group, the CERE group saw significant changes. [Conclusion] The results of application of CERE to chronic stroke patients demonstrated the importance of respiratory exercise in an approach to stroke rehabilitation treatment intervention and the need to add respiratory exercise to a rehabilitation intervention program.
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BACKGROUND/OBJECTIVES: This research was conducted to compare lecture-and experience-based methods of nutritional education as well as provide fundamental data for developing an effective nutritional education program in elementary schools. SUBJECTS/METHODS: A total of 110 students in three elementary schools in Jeollanam-do were recruited and randomly distributed in lecture-and experience-based groups. The effects of education on students' dietary knowledge, dietary behaviors, and dietary habits were analyzed using a pre/post-test. RESULTS: Lecture-and experience-based methods did not significantly alter total scores for dietary knowledge in any group, although lecture-based method led to improvement for some detailed questions. In the experience-based group, subjects showed significant alteration of dietary behaviors, whereas lecture-based method showed alteration of dietary habits. CONCLUSIONS: These outcomes suggest that lecture-and experience-based methods led to differential improvement of students' dietary habits, behaviors, and knowledge. To obtain better nutritional education results, both lectures and experiential activities need to be considered.