Twisted bilayer graphene (tBLG) provides a fascinating platform for engineering flat bands and inducing correlated phenomena. By designing the stacking architecture of graphene layers, twisted multilayer graphene can exhibit different symmetries with rich tunability. For example, in twisted monolayer-bilayer graphene (tMBG) which breaks the C2z symmetry, transport measurements reveal an asymmetric phase diagram under an out-of-plane electric field, exhibiting correlated insulating state and ferromagnetic state respectively when reversing the field direction. Revealing how the electronic structure evolves with electric field is critical for providing a better understanding of such asymmetric field-tunable properties. Here we report the experimental observation of field-tunable dichotomic electronic structure of tMBG by nanospot angle-resolved photoemission spectroscopy (NanoARPES) with operando gating. Interestingly, selective enhancement of the relative spectral weight contributions from monolayer and bilayer graphene is observed when switching the polarity of the bias voltage. Combining experimental results with theoretical calculations, the origin of such field-tunable electronic structure, resembling either tBLG or twisted double-bilayer graphene (tDBG), is attributed to the selectively enhanced contribution from different stacking graphene layers with a strong electron-hole asymmetry. Our work provides electronic structure insights for understanding the rich field-tunable physics of tMBG.
Interactions among charge carriers in graphene can lead to the spontaneous breaking of multiple degeneracies. When increasing the number of graphene layers following rhombohedral stacking, the dominant role of Coulomb interactions becomes pronounced due to the significant reduction in kinetic energy. In this study, we employ phonon-polariton-assisted near-field infrared imaging to determine the stacking orders of tetralayer graphene devices. Through quantum transport measurements, we observe a range of spontaneous broken-symmetry states and their transitions, which can be finely tuned by carrier density n and electric displacement field D. Specifically, we observe a layer-antiferromagnetic insulator at n = D = 0 with a gap of approximately 15 meV. Increasing D allows for a continuous phase transition from a layer-antiferromagnetic insulator to a layer-polarized insulator. By simultaneously tuning n and D, we observe isospin-polarized metals, including spin-valley-polarized and spin-polarized metals. These transitions are associated with changes in the Fermi surface topology and are consistent with the Stoner criteria. Our findings highlight the efficient fabrication of specially stacked multilayer graphene devices and demonstrate that crystalline multilayer graphene is an ideal platform for investigating a wide range of broken symmetries driven by Coulomb interactions.
Purpose: This study investigated the incidence of secondary malignancy in multiple myeloma (MM) patients compared with that in the general population using a population-based database covering all residents in Korea. Materials and Methods: Based on the national health insurance system in Korea, all people primarily diagnosed with MM between January 1, 2010 to December 31, 2018 were identified. A total of 9,985 MM patients aged ≥20 years in Korea were included. Results: Among them, 237 (2.4%) developed secondary malignancies by 2018. The standardized incidence rates (SIRs) of all secondary malignancies in MM patients were 0.87 (95% confidence interval [CI]=0.76-0.98), with a higher incidence of hematologic malignancies than in the general population with an SIR of 3.80 (95% CI=2.61-5.00). The incidence rates of both lymphoid malignancy (SIR=3.56; 95% CI=2.31-4.82) and myeloid malignancy (SIR=3.78; 95% CI=1.16-6.39) were higher in MM patients than in the general population. In contrast, a lower incidence of solid cancer was observed in MM patients than in the general population (SIR=0.76, 95% CI=0.65-0.86). There was no significant difference in survival in MM patients without secondary malignancies, with hematologic malignancy, and with solid cancer (p-value=0.413). Conclusion: MM patients had a greater risk of secondary malignancies, especially hematologic malignancies, than the general population. Future studies with a focus on analyzing patients' history, treatment details, and genetic information in various stages of MM patients are needed to better understand the mechanism behind this increased risk.
Recent experiments in magic-angle twisted bilayer graphene have revealed a wealth of novel electronic phases as a result of interaction-driven spin-valley flavour polarisation. In this work, we investigate correlated phases due to the combined effect of spin-orbit coupling-enhanced valley polarisation and the large density of states below half filling of the moiré band in twisted bilayer graphene coupled to tungsten diselenide. We observe an anomalous Hall effect, accompanied by a series of Lifshitz transitions that are highly tunable with carrier density and magnetic field. The magnetisation shows an abrupt change of sign near half-filling, confirming its orbital nature. While the Hall resistance is not quantised at zero magnetic fields-indicating a ground state with partial valley polarisation-perfect quantisation and complete valley polarisation are observed at finite fields. Our results illustrate that singularities in the flat bands in the presence of spin-orbit coupling can stabilise ordered phases even at non-integer moiré band fillings.
Graphite , Electronics , Environment , Excipients , Magnetic Fields
Ankylosing spondylitis (AS) is a chronic inflammatory arthritis which causes potentially debilitating pain and loss of mobility. Biologics represent a highly effective treatment option in AS. Nonetheless, the choice of biologics often involves complex decision-making. A web-based medical communication aid (MCA) was designed to support information exchange and shared decision-making process between physicians and biologics naïve AS patients. This study aimed to assess the usability of the MCA prototype and the understandability of the MCA contents among rheumatologists and AS patients in South Korea. This was a cross-sectional study using a mixed-methods approach. Treating rheumatologists from major hospitals and their AS patients were recruited in this study. Participants navigated through the MCA and provided feedbacks, guided by interviewers using the think-aloud (TA) method. Participants were then asked to complete a set of surveys. The qualitative and quantitative data were analyzed to determine the usability of the MCA prototype and the understandability of the MCA contents. The MCA prototype received above average rating for usability and high rating for the understandability of its contents. Additionally, participants rated that the quality of information presented in the MCA as high. Analysis of the qualitative data highlighted three key aspects of the MCA; the usefulness of the MCA, the need to present concise and relevant content; and the importance of an intuitively designed tool. Overall, participants found the MCA to be potentially valuable in supporting the current unmet needs in clinical care and had expressed a willingness to use the MCA. The MCA had great potential in supporting shared decision-making by improving patients' knowledge on disease and treatment options, as well as clarifying patients' personal preferences and values in the management of AS.
Spondylitis, Ankylosing , Humans , Spondylitis, Ankylosing/therapy , Cross-Sectional Studies , Treatment Outcome , Communication , Internet
Acrylic pressure-sensitive adhesives (PSAs) are used as fixatives between layers of a display. PSAs' function is an important factor that determines the performance of the display. Of the various display types available, the touch screen panel (TSP) of smart devices is firmly related to the relative permittivity of the elementals. Therefore, adjusting the relative permittivity of the PSA is indispensable for driving the TSP. Accordingly, selected acrylic pre-polymers were polymerized and the pre-polymer was blended and cross-linked with monomers with different chemical structure to adjust the relative permittivity. The monomers were hexametyldisiloxane (HMDS), N-vinylcaprolactam (NVC), tert-butyl acrylate (TBA), and isooctadecyl acrylate (ISTA). The gel fraction and transmittance as a function of the monomers show a similar result to the pure acrylic PSA. However, the gel fraction value decreased to about 90% and the transmittance decreased to about 85%, due to the immiscibility between nonpolar HMDS and acrylic PSA. On the other hand, the adhesion properties were improved when NVC was added because of the polarity of the nitrogen group. In addition, the relative permittivity of the PSA decreased regardless of the monomer chosen. There was, however, a difference in the optimal content of each monomer, and NVC decreased from 4 phr content to about 3.4 in reducing relative permittivity. Through the above results, it was confirmed that NVC having a nitrogen group is most advantageous in lowering adhesion properties and relative permittivity, and necessitates further research based on the findings.
This study was conducted to evaluate the insecticidal effects of ethyl formate (EF), methyl bromide (MB), and phosphine (PH3) fumigants against PH3-susceptible and -resistant strains of the rice weevil (Sitophilus oryzae), a major rice pest. The highest lethal concentration time 50 (LCt50) values of the PH3-susceptible strains were 255.797, 21.104, and 6.171 mg h L-1 for EF, MB, and PH3, respectively, at pupal stage. The highest LCt50 values of the PH3-resistant strains were 149.028 and 48.170 mg h L-1 for EF and PH3, respectively, at late larval stage, and 43.520 mg h L-1 for MB at pupal stage. In comparison to the susceptible strains, the PH3-resistant strain collected in South Korea had a resistance level 4 to 56 times higher. Use of the major quarantine fumigants EF, MB, and PH3 indicated the existence of PH3-resistant rice weevils in South Korea for the first time.
This study investigated the effect of different photoperiods (14L: 10D, 12L:12D and 10L:14D) on the gonadal development and GtH mRNA expression in the pituitary of damselfish. The results showed that gonadosomatic index (GSI) was significantly lower in shot photoperiod (10L:14D), in comparison with other photoperiodic group during the spawning season. After 60 days treatment, histological analysis of gonad tissue showed that the gonad of 10L:14D and 12L: 12D treatment groups were resting phase with spermatogonia and perinucleolus stage oocytes but the gonad of 14L:10D treatment group was still ripe phase with spermatozoa and mature stage oocyte. The FSHß and LHß mRNA expression in pituitary drastically decreased shot photoperiod treatment from July (spawning period). These results suggest that photoperiod is considered to be the most effective environmental factor in controlling the reproductive cycle of damselfish.
[Purpose] The aim of this study was to examine the effects of community-based rehabilitation program in chronic stroke patients. [Subjects and Methods] Eleven subjects received community-based rehabilitation program ten times for ten months. The main outcome measures were the Modified Barthel Index score for activities of daily living and the Korean Mini-Mental State Examination score for cognition. [Results] The results of the study demonstrated that the community-based rehabilitation program improved activities of daily living performance and cognition significantly. [Conclusion] Based on the study results, the community-based rehabilitation program is an effective method for improving activities of daily living performance and cognitive function in elderly patients with chronic stroke.
OBJECTIVE: The aims of this study were to investigate a simple method for assessing anterior-posterior jaw relationships via cone-beam computed tomography (CBCT) images taken in the natural head position (NHP) relative to the nasion true vertical plane (NTVP), and measure normative data in Korean adults with normal profiles. METHODS: Subjects were selected from patients presenting for third molar extraction and evaluated as having normal profiles by three examiners. The CBCT images of 80 subjects (39 males, 41 females) were taken in the NHP according to Solow and Tallgren's method. Linear measurements of the A-point, B-point, and Pog were calculated relative to the NTVP. Student's t-test was used to assess sexual differences in these measurements. RESULTS: The mean linear measurements of the A-point, B-point, and Pog relative to the NTVP were 0.18 mm (standard deviation [SD], 4.77 mm), -4.00 mm (SD, 6.62 mm), and -2.49 mm (SD, 7.14 mm) respectively in Korean males, and 1.48 mm (SD, 4.21 mm), -4.07 mm (SD, 6.70 mm) and -2.91 mm (SD, 7.25 mm) in Korean females respectively. There were no statistically significant differences between Korean males and females (p < 0.05). CONCLUSIONS: Three-dimensional CBCT analysis using the NTVP is a simple and reliable method for assessing anterior-posterior skeletal relationships.
[Purpose] The purpose of this study was to determine the effects of the Otago exercise program on fall efficacy, activities of daily living, and quality of life in elderly stroke patients. [Subjects and Methods] Eight subjects performed the Otago exercise program three times per week, for 8 weeks. The outcome measures were the Fall Efficacy Scale score for fall efficacy, modified Barthel index for activities of daily living, and EQ-5D for quality of life. [Results] In our comparison of the results before and after the intervention, we found that the Otago exercise program improved fall efficacy significantly as well as the score for activities of daily living and quality of life, though not significantly. [Conclusion] We consider that the Otago exercise program is an effective method for improving fall efficacy in elderly stroke patients.
[Purpose] The purpose of this study was to find evidence for the effectiveness of rehabilitation for pain relief in patients with rheumatoid arthritis. [Subjects and Methods] A systematic review was conducted of MEDLINE, The Cochrane Central Register of Controlled Trials (CENTRAL), and OVID, for studies published from July 2005 to July 2015. We extracted data regarding patients, intervention, comparison, and outcomes, and assessed the methodological quality of the data. [Results] Nine randomized controlled trials comparing the effects of pain relief in patients with rheumatoid arthritis were found. [Conclusion] Physical therapy and occupational therapy can reduce pain in rheumatoid arthritis.
BACKGROUND: The inferior alveolar nerve (IAN) may be injured during extraction of the mandibular third molar, causing severe postoperative complications. Many methods have been described for evaluating the relative position between the mandibular third molar and the inferior alveolar canal (IAC) on panoramic radiography and computed tomography, but conventional radiography provides limited information on the proximity of these two structures. The present study assessed the benefits of three-dimensional computed tomography (3D-CT) prior to surgical extraction of the mandibular third molar, to prevent IAN damage. METHODS: This retrospective study included 4917 extractions in 3555 patients who presented for extraction of the mandibular third molars. The cases were classified into three groups, according to anatomical relationship between the mandibular third molars and the IAC on panoramic radiography and whether 3D-CT was performed. Symptoms of IAN damage were assessed using the touch-recognition test. Data were compared using the chi-square test and Fisher's exact test. RESULTS: Among the 32 cases of IAN damage, 6 cases were included in group I (0.35 %, n = 1735 cases), 23 cases in group II (1.1 %, n = 2063 cases), and 3 cases in group III (0.27 %, n = 1119 cases). The chi-square test showed a significant difference in the incidence of IAN damage between groups I and II. No significant difference was observed between groups I and III using Fisher's exact test. In the 6 cases of IAN damage in group I, the mandibular third molar roots were located lingual relative to the IAC in 3 cases and middle relative to the IAC in 3 cases. The overlap was ≥2 mm in 3 of 6 cases and 0-2 mm in the remaining 3 cases. The mean distance between the mandibular third molar and IAC was 2.2 mm, the maximum distance 12 mm, and the minimum distance 0.5 mm. Greater than 80 % recovery was observed in 15 of 32 (46.8 %) cases of IAN damage. CONCLUSIONS: 3D-CT may be a useful tool for assessing the three-dimensional anatomical relationship and proximity between the mandibular third molar and IAC in order to prevent IAN damage during extraction of mandibular third molars.
[Purpose] The purpose of this study was to determine the effects of mirror therapy with tasks on upper extremity unction and self-care in stroke patients. [Subjects] Thirty participants were randomly assigned to either an experimental group (n=15) or a control group (n=15). [Methods] Subjects in the experimental group received mirror therapy with tasks, and those in the control group received a sham therapy; both therapies were administered, five times per week for six weeks. The main outcome measures were the Manual Function Test for the paralyzed upper limb and the Functional Independence Measure for self-care performance. [Results] The experimental group had more significant gains in change scores compared with the control group after the intervention. [Conclusion] We consider mirror therapy with tasks to be an effective form of intervention for upper extremity function and self-care in stroke patients.
Lip/pathology , Malocclusion/therapy , Orthodontic Anchorage Procedures/instrumentation , Orthodontic Appliance Design , Orthodontic Brackets , Tooth Movement Techniques/instrumentation , Adult , Bicuspid/surgery , Cephalometry/methods , Female , Follow-Up Studies , Humans , Malocclusion/pathology , Orthodontic Wires , Palate/pathology , Patient Care Planning , Tooth Extraction
OBJECTIVE: The aim of this study was to compare new bone formation with titanium (Ti) surface and hydroxyapatite (HA)-coated titanium surface in mucosal perforation model. MATERIALS AND METHODS: HA coating to the Ti disc and implant were done by aerosol deposition technique. Alkaline phosphatase assay and cell migration assay were done in Ti and HA surface disc with MG63 cells. For the in vivo test, 5 New Zealand white rabbits were used. Two penetration defects were prepared in the nasal bone. Subsequently, 2 types of implants were installed into the defect (diameter: 3.0 mm, length: 6.0 mm). Approximately 5.0 mm of the fixture's surface penetrated into the nasal cavity. In the experimental group, HA-coated implants were used. The same design of implants without coating was used in the control group. The animals were sacrificed 8 weeks postoperatively. Subsequently, a histomorphometric analysis was done. RESULTS: Alkaline phosphatase activity was significantly higher in HA-coated surface than in titanium surface (P < 0.05). In addition, more cells were migrated into the HA-coated surface when compared to Ti surface. In the animal experiments, mean new bone formation was 30.68 ± 14.16% in the experimental group and 6.92 ± 5.12% in the control group (P = 0.001). Mean bone-to-implant contact was 31.71 ± 8.41% in the experimental group and 7.98 ± 5.58% in the control group (P < 0.001). Mean height of the bone regeneration was 3.70 ± 0.76 mm in the experimental group and 1.04 ± 0.67 mm in the control group. The difference between the 2 groups was statistically significant (P < 0.001). CONCLUSIONS: HA-coated implants exhibited more bone regeneration in the mucosal penetration model than the uncoated implants.
Durapatite/pharmacology , Nasal Bone/surgery , Osteogenesis/drug effects , Prostheses and Implants , Titanium/pharmacology , Aerosols , Alkaline Phosphatase/analysis , Animals , Cell Movement/drug effects , Coated Materials, Biocompatible , Microscopy, Electron, Scanning , Nasal Bone/enzymology , Rabbits
Cephalometry/standards , Malocclusion, Angle Class III/surgery , Orthognathic Surgical Procedures/standards , Anatomic Landmarks , Humans , Male , Mandible/surgery , Osteotomy, Sagittal Split Ramus , Patient Care Planning , Posture , Prognathism/surgery , Reference Standards , Reproducibility of Results , Young Adult
Graphene's single atomic layer of sp(2) carbon has recently garnered much attention for its potential use in electronic applications. Here, we report a memory application for graphene, which we call graphene flash memory (GFM). GFM has the potential to exceed the performance of current flash memory technology by utilizing the intrinsic properties of graphene, such as high density of states, high work function, and low dimensionality. To this end, we have grown large-area graphene sheets by chemical vapor deposition and integrated them into a floating gate structure. GFM displays a wide memory window of â¼6 V at significantly low program/erase voltages of ±7 V. GFM also shows a long retention time of more than 10 years at room temperature. Additionally, simulations suggest that GFM suffers very little from cell-to-cell interference, potentially enabling scaling down far beyond current state-of-the-art flash memory devices.
Computer Storage Devices , Graphite , Electric Capacitance
High quality, large grain size graphene on polycrystalline nickel film on two inch silicon wafers was successfully synthesized by the chemical vapor deposition (CVD) method. The polydimethylsiloxane (PDMS) stamping method was used for graphene transferring in this experiment. The graphene transferred onto Al2O3/ITO substrates was patterned into macroscopic dimension electrodes using conventional lithography followed by oxygen plasma etching. Experimental results show that this graphene can serve as transparent source and drain electrodes in high performance organic semiconductor nanoribbon organic field-effect transistors (OFETs), facilitating high hole injection efficiency due to the preferred work function match with the channel material: single crystalline copper phthalocyanine (CuPc) nanoribbons. The nanoribbons were grown on top of the patterned graphene via evaporate-deposition to form the FET device. The carrier mobility and on/off current ratio of such devices were measured to be as high as 0.36 cm2/(V s) and 10(4).
