Using GPT-4 for LI-RADS feature extraction and categorization with multilingual free-text reports.

BACKGROUND AND AIMS: The Liver Imaging Reporting and Data System (LI-RADS) offers a standardized approach for imaging hepatocellular carcinoma. However, the diverse styles and structures of radiology reports complicate automatic data extraction. Large language models hold the potential for structured data extraction from free-text reports. Our objective was to evaluate the performance of Generative Pre-trained Transformer (GPT)-4 in extracting LI-RADS features and categories from free-text liver magnetic resonance imaging (MRI) reports. METHODS: Three radiologists generated 160 fictitious free-text liver MRI reports written in Korean and English, simulating real-world practice. Of these, 20 were used for prompt engineering, and 140 formed the internal test cohort. Seventy-two genuine reports, authored by 17 radiologists were collected and de-identified for the external test cohort. LI-RADS features were extracted using GPT-4, with a Python script calculating categories. Accuracies in each test cohort were compared. RESULTS: On the external test, the accuracy for the extraction of major LI-RADS features, which encompass size, nonrim arterial phase hyperenhancement, nonperipheral 'washout', enhancing 'capsule' and threshold growth, ranged from .92 to .99. For the rest of the LI-RADS features, the accuracy ranged from .86 to .97. For the LI-RADS category, the model showed an accuracy of .85 (95% CI: .76, .93). CONCLUSIONS: GPT-4 shows promise in extracting LI-RADS features, yet further refinement of its prompting strategy and advancements in its neural network architecture are crucial for reliable use in processing complex real-world MRI reports.

Interobserver Variability and Diagnostic Performance in Predicting Malignancy of Pancreatic Intraductal Papillary Mucinous Neoplasm with MRI.

Background The 2017 international consensus guidelines for intraductal papillary mucinous neoplasm (IPMN) of the pancreas are widely used. Purpose To evaluate the interobserver agreement and diagnostic performance of MRI assessment in predicting the malignant potential of IPMN according to radiologists' experience. Materials and Methods This multicenter retrospective study included 100 patients with pathologically proven pancreatic IPMN (77 patients with surgery, 23 patients with biopsy) who underwent contrast-enhanced MRI between 2016 and 2021. Eight post-fellowship radiologists (four more-experienced [8-20 years] and four less-experienced [1-4 years] reviewers) evaluated MRI for high-risk stigmata and worrisome features identified by the most recent 2017 guidelines. Interobserver agreement was determined using Fleiss κ statistics according to radiologist experience. The diagnostic performance for malignant IPMN was assessed using receiver operating characteristic curve analysis. Results Among 100 patients (mean age, 66 years ± 10 [SD]; 57 men), 52 (52%) had malignant IPMN. For high-risk stigmata, interobserver agreement was substantial for main pancreatic duct size of at least 10 mm (κ = 0.78; 95% CI: 0.75, 0.82), enhancing mural nodule of at least 5 mm (κ = 0.70: 95% CI: 0.66, 0.74), and at least one high-risk stigmata (κ = 0.73: 95% CI: 0.69, 0.76). The worrisome features showed fair to substantial interobserver agreement (κ range, 0.22-0.80). More-experienced reviewers demonstrated better agreement in the assessment of at least one high-risk stigmata than less-experienced reviewers (κ = 0.77 vs κ = 0.69, P < .001). The overall diagnostic performance of each reviewer was good for the prediction of malignant pancreatic IPMN (area under the receiver operating characteristic curve [AUC] range, 0.77-0.84; median AUC, 0.82), with substantial agreement (κ = 0.76). Conclusion The 2017 international consensus guidelines enabled good diagnostic performance and substantial interobserver agreement for high-risk stigmata but not worrisome features on the evaluation of the malignant pancreatic IPMN using MRI. Agreement tended to be better among more-experienced reviewers than among less-experienced reviewers. © RSNA, 2023 Supplemental material is available for this article.

Utility of accelerated T2-weighted turbo spin-echo imaging with deep learning reconstruction in female pelvic MRI: a multi-reader study.

OBJECTIVES: To determine the clinical feasibility of T2-weighted turbo spin-echo (T2-TSE) imaging with deep learning reconstruction (DLR) in female pelvic MRI compared with conventional T2 TSE in terms of image quality and scan time. METHODS: Between May 2021 and September 2021, 52 women (mean age, 44 years ± 12) who underwent 3-T pelvic MRI with additional T2-TSE using a DLR algorithm were included in this single-center prospective study with patient's informed consents. Conventional, DLR, and DLR T2-TSE images with reduced scan times were independently assessed and compared by four radiologists. The overall image quality, differentiation of anatomic details, lesion conspicuity, and artifacts were evaluated using a 5-point scale. Inter-observer agreement of the qualitative scores was compared and reader protocol preferences were then evaluated. RESULTS: In the qualitative analysis of all readers, fast DLR T2-TSE showed significantly better overall image quality, differentiation of anatomic regions, lesion conspicuity, and lesser artifacts than conventional T2-TSE and DLR T2-TSE, despite approximately 50% reduction in scan time (all p < 0.05). The inter-reader agreement for the qualitative analysis was moderate to good. All readers preferred DLR over conventional T2-TSE regardless of scan time and preferred fast DLR T2-TSE (57.7-78.8%), except for one who preferred DLR over fast DLR T2-TSE (53.8% vs. 46.1%). CONCLUSION: In female pelvic MRI, image quality and accelerated image acquisition for T2-TSE can be significantly improved by using DLR compared to conventional T2-TSE. Fast DLR T2-TSE was non-inferior to DLR T2-TSE in terms of reader preference and image quality. CLINICAL RELEVANCE STATEMENT: DLR of T2-TSE in female pelvic MRI enables fast imaging along with maintaining optimal image quality compared with parallel imaging-based conventional T2-TSE. KEY POINTS: • Conventional T2 turbo spin-echo based on parallel imaging has limitations for accelerated image acquisition while maintaining good image quality. • Deep learning image reconstruction showed better image quality in both images obtained using the same or accelerated image acquisition parameters compared with conventional T2 turbo spin-echo in female pelvic MRI. • Deep learning image reconstruction enables accelerated image acquisition while maintaining good image quality in the T2-TSE of female pelvic MRI.

Cerenkov luminescence imaging of interscapular brown adipose tissue using a TSPO-targeting PET probe in the UCP1 ThermoMouse.

Rationale: [18F]fluorodeoxyglucose-positron emission tomography ([18F]FDG-PET) has been widely used as an imaging technique to measure interscapular brown adipose tissue (iBAT) activity. However, it is challenging to obtain iBAT-specific images using [18F]FDG-PET because increased uptake of [18F]FDG is observed in tumors, muscle, and inflamed tissues. Uncoupling protein 1 (UCP1) in the mitochondrial membrane, a well-known molecular marker of BAT, has been proposed as a useful BAT imaging marker. Recently, the UCP1 ThermoMouse was developed as a reporter mouse for monitoring UCP1 expression and investigating BAT activation. In addition, Translocator protein-18 kDa (TSPO) located in the outer mitochondrial membrane is also overexpressed in BAT, suggesting that TSPO-targeting PET has potential for iBAT imaging. However, there are no studies monitoring BAT using TSPO-targeting PET probes in the UCP1 ThermoMouse. Moreover, the non-invasive Cerenkov luminescence imaging (CLI) using Cerenkov radiation from the PET probe has been proposed as an alternative option for PET as it is less expensive and user-friendly. Therefore, we selected [18F]fm-PBR28-d 2 as a TSPO-targeting PET probe for iBAT imaging to evaluate the usefulness of CLI in the UCP1 ThermoMouse. Methods: UCP1 ThermoMouse was used to monitor UCP1 expression. Western blotting and immunohistochemistry were performed to measure the level of protein expression. [18F]fm-PBR28-d 2 and [18F]FDG were used as radioactive probes for iBAT imaging. PET images were acquired with SimPET, and optical images were acquired with IVIS 100. Results: UCP1 ThermoMouse showed that UCP1 and TSPO expressions were correlated in iBAT. In both PET and CLI, the TSPO-targeting probe [18F]fm-PBR28-d 2 was superior to [18F]FDG for acquiring iBAT images. The high molar activity of the probe was essential for CLI and PET imaging. We tested the feasibility of TSPO-targeting probe under cold exposure by imaging with TSPO-PET/CLI. Both signals of iBAT were clearly increased after cold stimulation. Under prolonged isoflurane anesthesia, TSPO-targeting images showed higher signals from iBAT in the short-term than in long-term groups. Conclusion: We demonstrated that TSPO-PET/CLI reflected UCP1 expression in iBAT imaging better than [18F]FDG-PET/CLI under the various conditions. Considering convenience and cost, TSPO-CLI could be used as an alternative TSPO-PET technique for iBAT imaging.

Clinical feasibility of accelerated diffusion weighted imaging of the abdomen with deep learning reconstruction: Comparison with conventional diffusion weighted imaging.

PURPOSE: To assess the clinical feasibility of accelerated deep learning-reconstructed diffusion weighted imaging (DWI) and to compare its image quality and acquisition time with those of conventional DWI. METHODS: Seventy-four consecutive patients who underwent 3 T abdominal magnetic resonance imaging (MRI) were retrospectively enrolled. DWI were acquired using both conventional DWI and DWI with deep-learning reconstruction (DL DWI). Image quality (overall image quality, anatomic sharpness and details, artifacts, noise, and lesion conspicuity) was scored by two radiologists and compared between two DWI sequences. The apparent diffusion coefficient (ADC) was measured in six locations of the liver parenchyma and focal lesions and compared between two DWI sequences. RESULTS: The mean acquisition time for the DL DWI (216.87 ± 49.23 sec) was significantly shorter (P < 0.001) than for conventional DWI (358.69 ± 105.93 sec). DL DWI achieved higher scores than conventional DWI for all qualitative image quality parameters (P < 0.001). DL DWI had a more homogeneous distribution of ADC values throughout the liver, except for the left superior section, compared with conventional DWI. The standard deviations of the ADC values for all hepatic areas were significantly lower in DL DWI than in conventional DWI (all, P < 0.001). The ADC values for the liver parenchyma and focal hepatic lesions were lower in DL DWI than in conventional DWI. CONCLUSIONS: DL DWI is a feasible acquisition technique in clinical routines and provides improved image quality and simultaneously significant reduction in scan time compared with conventional DWI.

Clinical Feasibility of Shear Wave Dispersion Slope for Noninvasive Diagnosis of Nonalcoholic Steatohepatitis in Patients With Morbid Obesity: Preliminary Results Using US Shear Wave Elastography.

ABSTRACT: We aimed to investigate the clinical feasibility of shear wave dispersion slope for assessing nonalcoholic steatohepatitis (NASH) in patients with morbid obesity before bariatric surgery.This prospective study collected data from 25 participants who received liver biopsy during bariatric surgery between February 2019 and December 2020. All participants underwent ultrasonography shear wave elastography before surgery and shear wave speed and shear wave dispersion slope were measured. Liver specimens were evaluated by 1 pathologist scored histologically for nonalcoholic fatty liver disease (NAFLD). Ultrasonography measurements were compared according to histopathologic findings. Diagnostic performance in differentiating NASH from NAFLD was evaluated using the area under the receiver operating characteristic curve (AUC). Median shear wave speed (1.48 vs 1.62 m/s, P = 0.014) and dispersion slope (8.40 vs 11.80 [m/s]/kHz, P = 0.004) were higher in NASH group than in NAFLD group. Shear wave dispersion slope tended to increase step by step as the severity of activity grade (P = 0.032) and hepatic fibrosis (P = 0.015) increased. The AUC of shear wave dispersion slope for differentiating NASH from NAFLD (AUC, 0.83; 95% confidence intervals, 0.66-1.00) was higher than that of shear wave speed (AUC, 0.78; 95% CI, 0.60-0.97), although it did not reach statistical significance (P = 0.729). Shear wave dispersion slope could be a feasible tool for assessing NASH in patients with morbid obesity.

Acute Ectopic Pancreatitis Mimicking Peptic Ulcer Disease: A Case Report.

BACKGROUND: The ectopic pancreas is an anatomically separate pancreatic tissue from normal glands with its own vascular and ductal system; it is most commonly found in the upper gastrointestinal tract. The ectopic pancreas is usually asymptomatic, but it can present with symptoms associated with complications, including bleeding, inflammation, and neoplasm without abnormalities in the normal pancreas. CASE PRESENTATION: We report a 31-year-old female with acute ectopic pancreatitis involving gastric antrum and proximal duodenum mimicking peptic ulcer disease, without pancreatitis in the normal pancreas. CONCLUSION: Ectopic pancreatitis is a rare condition and can mimic more common diseases depending on the anatomical location.

Supraparticle Engineering for Highly Dense Microspheres: Yttria-Stabilized Zirconia with Adjustable Micromechanical Properties.

Various supraparticles have been extensively studied owing to their excellent catalytic properties that are attributed to their inherent porous structure; however, their mechanical properties have not garnered attention owing to their less dense structure. We demonstrate a rational approach for fabricating assembled supraparticles and, subsequently, highly dense microspheres. In addition, 3 mol % yttria-stabilized zirconia (3YSZ) and alumina particles were selected as building blocks and assembled into higher-order architectures using a droplet-based template method (spray drying) for validation with proof-of-concept. Moreover, structural features such as density, size, sphericity, and morphology of supraparticles were controlled by adjusting the competing kinetics occurring between the assembly of building blocks and evaporation of the solvent in the droplets. The preparatory aqueous suspension and process parameters were optimized as well. A detailed understanding of the formation mechanism facilitated the yield of tailor-made supraparticles and, thereafter, highly dense microspheres (approximate relative density = 99%) with excellent sphericity (>98%) via heat treatment. The microspheres displayed highest hardness (26.77 GPa) and superior elastic modulus (210.19 GPa) compared with the mechanical properties of the 3YSZ samples reported to date. Ultimately, the proposed supraparticle engineering provided insight for controlling the structural features and resultant micromechanical properties, which widely extends the applicability of supraparticle-based functional materials for practical purposes that require materials with high density and excellent mechanical properties.

Asymptomatic Transmission of SARS-CoV-2 on Evacuation Flight.

We conducted a cohort study in a controlled environment to measure asymptomatic transmission of severe acute respiratory syndrome coronavirus 2 on a flight from Italy to South Korea. Our results suggest that stringent global regulations are necessary for the prevention of transmission of this virus on aircraft.

[18F]CB251 PET/MR imaging probe targeting translocator protein (TSPO) independent of its Polymorphism in a Neuroinflammation Model.

The 18 kDa translocator protein (TSPO) has been proposed as a biomarker for the detection of neuroinflammation. Although various PET probes targeting TSPO have been developed, a highly selective probe for detecting TSPO is still needed because single nucleotide polymorphisms in the human TSPO gene greatly affect the binding affinity of TSPO ligands. Here, we describe the visualization of neuroinflammation with a multimodality imaging system using our recently developed TSPO-targeting radionuclide PET probe [18F]CB251, which is less affected by TSPO polymorphisms. Methods: To test the selectivity of [18F]CB251 for TSPO polymorphisms, 293FT cells expressing polymorphic TSPO were generated by introducing the coding sequences of wild-type (WT) and mutant (Alanine → Threonine at 147th Amino Acid; A147T) forms. Competitive inhibition assay was conducted with [3H]PK11195 and various TSPO ligands using membrane proteins isolated from 293FT cells expressing TSPO WT or mutant-A147T, representing high-affinity binder (HAB) or low-affinity binder (LAB), respectively. IC50 values of each ligand to [3H]PK11195 in HAB or LAB were measured and the ratio of IC50 values of each ligand to [3H]PK11195 in HAB to LAB was calculated, indicating the sensitivity of TSPO polymorphism. Cellular uptake of [18F]CB251 was measured with different TSPO polymorphisms, and phantom studies of [18F]CB251-PET using 293FT cells were performed. To test TSPO-specific cellular uptake of [18F]CB251, TSPO expression was regulated with pCMV-TSPO (or shTSPO)/eGFP vector. Intracranial lipopolysaccharide (LPS) treatment was used to induce regional inflammation in the mouse brain. Gadolinium (Gd)-DOTA MRI was used to monitor the disruption of the blood-brain barrier (BBB) and infiltration by immune cells. Infiltration of peripheral immune cells across the BBB, which exacerbates neuroinflammation to produce higher levels of neurotoxicity, was also monitored with bioluminescence imaging (BLI). Peripheral immune cells isolated from luciferase-expressing transgenic mice were transferred to syngeneic inflamed mice. Neuroinflammation was monitored with [18F]CB251-PET/MR and BLI. To evaluate the effects of anti-inflammatory agents on intracranial inflammation, an inflammatory cytokine inhibitor, 2-cyano-3, 12-dioxooleana-1, 9-dien-28-oic acid methyl ester (CDDO-Me) was administered in intracranial LPS challenged mice. Results: The ratio of IC50 values of [18F]CB251 in HAB to LAB indicated similar binding affinity to WT and mutant TSPO and was less affected by TSPO polymorphisms. [18F]CB251 was specific for TSPO, and its cellular uptake reflected the amount of TSPO. Higher [18F]CB251 uptake was also observed in activated immune cells. Simultaneous [18F]CB251-PET/MRI showed that [18F]CB251 radioactivity was co-registered with the MR signals in the same region of the brain of LPS-injected mice. Luciferase-expressing peripheral immune cells were located at the site of LPS-injected right striatum. Quantitative evaluation of the anti-inflammatory effect of CDDO-Me on neuroinflammation was successfully monitored with TSPO-targeting [18F]CB251-PET/MR and BLI. Conclusion: Our results indicate that [18F]CB251-PET has great potential for detecting neuroinflammation with higher TSPO selectivity regardless of polymorphisms. Our multimodal imaging system, [18F]CB251-PET/MRI, tested for evaluating the efficacy of anti-inflammatory agents in preclinical studies, might be an effective method to assess the severity and therapeutic response of neuroinflammation.

A clinical review of reconstructive techniques for patients with multiple skin cancers on the face.

BACKGROUND: Cases of simultaneous multiple skin cancers in a single patient have become more common. Due to the multiplicity of lesions, reconstruction in such cases is more difficult than after a single lesion is removed. This study presents a series of patients with multiple facial skin cancers, with an analysis of the surgical removal, reconstruction process, and the results observed during follow-up. METHODS: We reviewed 12 patients diagnosed with multiple skin cancers on the face between November 2004 and March 2016. The patients' medical records were retrospectively reviewed to identify the type of skin cancer, the site of onset, methods of surgical removal and reconstruction, complications, and recurrence during follow-up. RESULTS: Nine patients had a single type of cancer occurring as multiple lesions, while three patients had different skin cancer types that occurred together. A total of 30 cancer sites were observed in the 12 patients. The most common cancer site was the nose. Thirteen defects were reconstructed with a flap, while 18 were reconstructed with skin grafting. The only complication was one case of recurrence of basal cell carcinoma. CONCLUSION: Multiple skin cancers are removed by performing Mohs micrographic surgery or wide excision, resulting in multiple defect sites. The authors emphasize the importance of thoroughly evaluating local lesions surrounding the initially-identified lesions or on other sites when reconstructing a large defect which can not be covered by primary closure. Furthermore, satisfactory results can be obtained by using various methods simultaneously regarding the condition of individual patients, the defect site and size, and the surgeon's preference.

The efficacy of elongated axillary incision on extended latissimus dorsi flap for immediate breast reconstruction.

BACKGROUND: In performing extended latissimus dorsi (ELD) flap procedures, a skin paddle design on the bra line helps reduce visible scarring. This improves the patient's satisfaction with the outcome. However, such a design leads to a longer operation time and increased fatigue of the surgeon due to the narrow operative field. In this study, the authors propose a method that elongates the axillary incision line posteriorly by 1.5 cm from the lateral border of the latissimus dorsi muscle. We examined whether this method could shorten the operation time and compared the incidence of complications between patients who underwent this novel procedure and patients who underwent the traditional procedure. METHODS: In this study of patients who underwent ELD flap procedures for immediate breast reconstruction, 89 underwent surgery with the elongated axillary incision and 45 underwent surgery without the elongated incision. The total operation time and complications were retrospectively examined based on the patients' medical records, and we examined whether there was any statistically significant difference in the total operation time. RESULTS: In the experimental group with the elongated axillary incision, the operation time ranged from 125 to 255 minutes (median, 175 minutes). In contrast, in the control group without the elongated axillary incision, the operation time ranged from 142 and 340 minutes (median, 205 minutes). The operation time was statistically significantly different between the two groups, and no significant complications were observed in the experimental group. CONCLUSIONS: Elongation of the axillary incision alone may shorten the operation time of the ELD flap procedure without causing additional complications.

Side branching and luminal lineage commitment by ID2 in developing mammary glands.

Mammary glands develop through primary ductal elongation and side branching to maximize the spatial area. Although primary ducts are generated by bifurcation of terminal end buds, the mechanism through which side branching occurs is still largely unclear. Here, we show that inhibitor of DNA-binding 2 (ID2) drives side branch formation through the differentiation of K6+ bipotent progenitor cells (BPs) into CD61+ luminal progenitor cells (LPs). Id2-null mice had side-branching defects, along with developmental blockage of the differentiation of K6+ BPs into CD61+ LPs. Notably, CD61+ LPs were found in budding and side branches, but not in terminal end buds. Hormone reconstitution studies using ovariectomized MMTV-hemagglutinin-nuclear localized sequence-tagged Id2 transgenic mice revealed that ID2 is a key mediator of progesterone, which drives luminal lineage differentiation and side branching. Our results suggest that CD61 is a marker of side branches and that ID2 regulates side branch formation by inducing luminal lineage commitment from K6+ BPs to CD61+ LPs.

Sex hormones establish a reserve pool of adult muscle stem cells.

Quiescent satellite cells, known as adult muscle stem cells, possess a remarkable ability to regenerate skeletal muscle following injury throughout life. Although they mainly originate from multipotent stem/progenitor cells of the somite, the mechanism underlying the establishment of quiescent satellite cell populations is unknown. Here, we show that sex hormones induce Mind bomb 1 (Mib1) expression in myofibres at puberty, which activates Notch signalling in cycling juvenile satellite cells and causes them to be converted into adult quiescent satellite cells. Myofibres lacking Mib1 fail to send Notch signals to juvenile satellite cells, leading to impaired cell cycle exit and depletion. Our findings reveal that the hypothalamic-pituitary-gonadal axis drives Mib1 expression in the myofibre niche. Moreover, the same axis regulates the re-establishment of quiescent satellite cell populations following injury. Our data show that sex hormones establish adult quiescent satellite cell populations by regulating the myofibre niche at puberty and re-establish them during regeneration.

Multiple Ewing Sarcoma/Primitive Neuroectodermal Tumors in the Mediastinum: A Case Report and Literature Review.

Ewing sarcoma/primitive neuroectodermal tumors (ES/PNET) are high-grade malignant neoplasms. These malignancies present very rare tumors of thoracopulmonary area and even rarer in the mediastinum. In our knowledge, ES/PNET presented with multiple mediastinal masses has not been reported previously. We experienced a case of a 42-year-old man presented with gradual onset of left-side pleuritic chest pain. A contrast-enhanced chest computed tomography (CT) scan showed separate 2 large heterogeneously enhancing masses in each anterior and middle mediastinum of the left hemithorax. Positron emission tomography-computed tomography (PET-CT) scan revealed high fluorodeoxyglucose (FDG) uptake in the mediastinal masses. After surgical excision for the mediastinal masses, both of the masses were diagnosed as the ES/PNET group of tumors on the histopathologic examination. The patient refused postoperative adjuvant chemotherapy and came back with local tumor recurrence and distant metastasis on 4-month follow-up after surgical resection. We report this uncommon form of ES/PNET. We are to raise awareness that this rare malignancy should be considered as a differential diagnosis of the malignant mediastinal tumors and which can be manifested as multiple masses in a patient. Understanding this rare entity of extra-skeletal ES/PNET and characteristic imaging findings can help radiologists and clinicians to approach proper diagnosis and better management for this highly malignant tumor.

The grain growth behavior of NiO in thermally-stable mesoporous gadolinium-doped ceria network for intermediate-temperature solid oxide fuel cell anode materials.

The grain growth behavior of NiO nano grains in mesoporous gadolinium-doped ceria (GDC) network was investigated for anode materials of intermediate-temperature solid oxide fuel cell (SOFC). Both mesoporous GDC and NiO-GDC powders were synthesized using tri-block copolymer, Pluronic F127 as a structure-directing agent, and then X-ray diffraction, N2 adsorption/desorption isotherms, thermo gravimetric analysis, field-emission scanning electron microscopy and transmission electron microscopy were used for characterization of the mesoporous structure. Mesoporous GDC synthesized using pluronic F127 triblock copolymer had ordered double mesoporous structure with an average pore size of 9.68 nm and was thermally stable up to 700 degrees C. NiO grains in the mesoporous GDC network grew to have an octahedral shape with truncated-edges, but massive NiO agglomeration occurred as the calcination temperature increases up to 850 degrees C.

The memristive properties of a single VO2 nanowire with switching controlled by self-heating.

A two-terminal memristor memory based on a single VO2 nanowire is reported that can not only provide switchable resistances in a large range of about four orders of magnitude but can also maintain the resistances by a low bias voltage. The phase transition of the single VO2 nanowire was driven by the bias voltage of 0.34 V without using any heat source. The memristive behavior of the single VO2 nanowire was confirmed by observing the switching and non-volatile properties of resistances when voltage pulses and low bias voltage were applied, respectively. Furthermore, multiple retainable resistances in a large range of about four orders of magnitude can be utilized by controlling the number and the amount of voltage pulses under the low bias voltage. This is a key step towards the development of new low-power and two-terminal memory devices for next-generation non-volatile memories.

Effect of the initial structure on the electrical property of crystalline silicon films deposited on glass by hot-wire chemical vapor deposition.

Crystalline silicon films on an inexpensive glass substrate are currently prepared by depositing an amorphous silicon film and then crystallizing it by excimer laser annealing, rapid thermal annealing, or metal-induced crystallization because crystalline silicon films cannot be directly deposited on glass at a low temperature. It was recently shown that by adding HCI gas in the hot-wire chemical vapor deposition (HWCVD) process, the crystalline silicon film can be directly deposited on a glass substrate without additional annealing. The electrical properties of silicon films prepared using a gas mixture of SiH4 and HCl in the HWCVD process could be further improved by controlling the initial structure, which was achieved by adjusting the delay time in deposition. The size of the silicon particles in the initial structure increased with increasing delay time, which increased the mobility and decreased the resistivity of the deposited films. The 0 and 5 min delay times produced the silicon particle sizes of approximately 10 and approximately 28 nm, respectively, in the initial microstructure, which produced the final films, after deposition for 300 sec, of resistivities of 0.32 and 0.13 Omega-cm, mobilities of 1.06 and 1.48 cm2 V(-1) S(-1), and relative densities of 0.87 and 0.92, respectively.

Electrical and optical properties of amorphous (In, Sn)-Ga-Zn-O thin film.

Films of amorphous In(1-x)Sn(x)GaZnO(delta) (a-ISGZO) (x = 0.0-1.0) were pulsed laser deposited at a temperature range of room temperature to 300 degrees C, and in order to systematically investigate the effect of replacing In with Sn on the properties of amorphous In-Ga-Zn-O (a-IGZO), the electrical and optical properties were measured. The amount of Sn in the deposited film, which was determined by X-ray photoelectron spectroscopy, was very close to the composition of the targets used. Hall mobility and carrier concentration decreased, and resistivity increased as the amount of Sn in the film increased. It was observed that the increase of Sn concentration in films was accompanied by the decrease of oxygen vacancy concentration, which led to the decrease of carrier concentration. The electrical mobility was decreased as the amount of Sn increased, which can be attributed to the increased number of subgap states, which was determined by the UV/VNIS spectrophotometer. Optical transparencies of all samples were larger than 80% in the visible light range. Band gap values were also found to increase as the amount of Sn increased.