Copper-Nanoparticle-Decorated Hydrothermal Carbonaceous Carbon-Polydimethylsiloxane Nanocomposites: Unveiling Potential in Simultaneous Light-Driven Interfacial Water Evaporation and Power Generation

This study introduces a hydrothermal synthesis method that uses glucose and Cu2+ ions to create a Cu-nanoparticle (NP)-decorated hydrothermal carbonaceous carbon hybrid material (Cu-HTCC). Glucose serves both as a reducing agent, efficiently transforming Cu2+ ions into elemental Cu nanostructures, and as a precursor for HTCC microstructures. An enhanced plasmon-induced electric field resulting from Cu NPs supported on microstructure matrices, coupled with a distinctive localized π-electronic configuration in the hybrid material, as confirmed by X-ray photoelectron spectroscopic analysis, lead to the heightened optical absorption in the visible-near-infrared range. Consequently, flexible nanocomposites of Cu-HTCC/PDMS and Cu-HTCC@PDMS (PDMS = polydimethylsiloxane) are designed as 2 and 3D structures, respectively, that exhibit broad-spectrum solar absorption. These composites promise efficient photo-assisted thermoelectric power generation and water evaporation, demonstrating commendable mechanical stability and flexibility. Notably, the Cu-HTCC@PDMS composite sponge simultaneously exhibits commendable efficiency in both water evaporation (1.47 kg m-2 h-1) and power generation (32.1 mV) under 1 sunlight illumination. These findings unveil new possibilities for innovative photothermal functional materials in diverse solar-driven applications.

Functionalized MXene ink enables environmentally stable printed electronics

Establishing dependable, cost-effective electrical connections is vital for enhancing device performance and shrinking electronic circuits. MXenes, combining excellent electrical conductivity, high breakdown voltage, solution processability, and two-dimensional morphology, are promising candidates for contacts in microelectronics. However, their hydrophilic surfaces, which enable spontaneous environmental degradation and poor dispersion stability in organic solvents, have restricted certain electronic applications. Herein, electrohydrodynamic printing technique is used to fabricate fully solution-processed thin-film transistors with alkylated 3,4-dihydroxy-L-phenylalanine functionalized Ti3C2Tx (AD-MXene) as source, drain, and gate electrodes. The AD-MXene has excellent dispersion stability in ethanol, which is required for electrohydrodynamic printing, and maintains high electrical conductivity. It outperformed conventional vacuum-deposited Au and Al electrodes, providing thin-film transistors with good environmental stability due to its hydrophobicity. Further, thin-film transistors are integrated into logic gates and one-transistor-one-memory cells. This work, unveiling the ligand-functionalized MXenes' potential in printed electrical contacts, promotes environmentally robust MXene-based electronics (MXetronics).

Well-Balanced Ambipolar Charge Transport of Diketopyrrolepyrrole-Based Copolymers: Organic Field-Effect Transistors and High-Voltage Logic Applications

A poly (3,6-bis(thiophen-2-yl)-2,5-bis(2-decyltetradecyl)-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione-co-(2,3-bis(phenyl)acrylonitrile)) (PDPADPP) copolymer, composed of diketopyrrolopyrrole (DPP) and a cyano (nitrile) group with a vinylene spacer linking two benzene rings, is synthesized via a palladium-catalyzed Suzuki coupling reaction. The electrical performance of PDPADPP in organic field-effect transistors (OFETs) and circuits is investigated. The OFETs based on PDPADPP exhibit typical ambipolar transport characteristics, with the as-cast OFETs demonstrating low field-effect hole and electron mobility values of 0.016 and 0.004 cm2  V-1  s-1 , respectively. However, after thermal annealing at 240 °C, the OFETs exhibit improved transport characteristics with highly balanced ambipolar transport, showing average hole and electron mobility values of 0.065 and 0.116 cm2  V-1  s-1 , respectively. To verify the application of the PDPADPP OFETs in high-voltage logic circuits, compact modeling using the industry-standard small-signal Berkeley short-channel IGFET model (BSIM) is performed, and the logic application characteristics are evaluated. The circuit simulation results demonstrate excellent logic application performance of the PDPADPP-based ambipolar transistor and illustrate that the device annealed at 240 °C exhibits ideal circuit characteristics.

Impact of pre-annealing process on electrical properties and stability of indium zinc oxide thin-film transistors

This paper examined the effects of no treatment versus plasma treatment, and femtosecond laser irradiation as pre-annealing processes on indium zinc oxide (IZO) films and annealing at high temperatures. The plasma pre-annealed multilayer stacked IZO TFTs showed better electrical properties with mobility enhancement from 2.45 to 7.81 cm2/Vs, but exhibited diminished on–off current ratio (Ion/Ioff). The IZO thin-film transistor (TFT) prepared with femtosecond laser pre-annealing with low pulse energy generation (power of 3 W at 700 nm wavelength) for 100 s has also exhibited significantly improved electrical performance, the saturation mobility increased to 4.91 cm2/Vs, the Ion/Ioff ratio was enhanced from 4.5 × 105 to 2.1 × 106, the threshold voltage improved from − 1.44 to − 0.25 V, and the subthreshold swing was reduced from 1.21 to 0.61 V/dec. In conclusion, IZO TFTs with improved performance can be prepared using a femtosecond laser pre-annealing process, which has great potential for fabricating low-cost, high-performance devices.

Clinical outcomes of new multifocal intraocular lenses with hydroxyethyl methacrylate and comparative results of contrast sensitivity, objective scatter, and subjective photic phenomena

Background

We investigate the performance of new hydrophobic diffractive multifocal intraocular lenses (IOL) with hydroxyethyl methacrylate (HEMA) and compare their optical quality, contrast sensitivity, and subjective photic phenomena.

Methods

Medical records of patients who underwent routine simple cataract surgery and insertion of an existing multifocal IOL (TFNT, TF group) or a new multifocal IOL (CNWT, CN group) were retrospectively reviewed. Clinical data was collected 2 months postoperatively and included optical quality analysis system (OQAS) indices, contrast sensitivity, and subjective degrees of photic phenomena.

Results

One hundred thirty-five eyes of 135 patients were included (CN group, 71; TF group, 64). There was no significant difference between the two groups in the visual acuity and defocus curve. The indices of OQAS did not show a significant difference between groups. Contrast sensitivity was significantly better in the CN group at all degrees, including the area under the log contrast sensitivity function (p = 0.01). The subjective photic phenomena survey showed better results for the CN group, with the proportion of patients reporting no photic phenomena as 9.9% and 3.1% in the CN and TF groups, respectively. The proportion of patients who reported severe photic phenomena was 11.3% in the CN group and 25.0% in the TF group. Although the follow-up period was only 2 months, glistening, surface scattering, and posterior capsule opacity were not observed in any patient.

Conclusions

The new multifocal IOL with HEMA is safe, and provides stable visual acuity as well as superior contrast sensitivity and lower subjective photic phenomena, over the prior IOL.

Electrohydrodynamic-Jet-Printed Phthalimide-Derived Conjugated Polymers for Organic Field-Effect Transistors and Logic Gates

A π-conjugated polymer semiconductor, PBDTTTffPI, was synthesized for use as an organic semiconductor suitable for electrohydrodynamic (EHD) jet printing technology. Bulky alkylation of the polymer gave PBDTTTffPI good solubility in several organic solvents. EHD jet printing using PBDTTTffPI ink produced direct patterns of polymer semiconductors while maintaining smooth surface morphologies and crystal structures similar to those of spin-coated PBDTTTffPI films. EHD-jet-printed PBDTTTffPI was appropriate for use as a semiconductor layer in organic field-effect transistors (OFETs) and logic gates. OFETs that used EHD-jet-printed PBDTTTffPI had better electrical characteristics than devices that used spin-coated semiconductor films. When a dielectric material (Al₂O₃) with a high dielectric constant was introduced, the jet-printed PBDTTTffPI operated well at low voltages. Integrated devices such as inverters, NAND gates, and NOR gates were fabricated by printing PBDTTTffPI patterns and showed good switching behaviors. Therefore, the use of printable PBDTTTffPI provides an advance toward fabrication of practical integrated arrays in next-generation devices.

Idiopathic Retroperitoneal Hematoma with Spontaneous Resolution

A 54-year-old man was transferred from another hospital due to a hematoma in the third portion of the duodenum on abdomen CT. He had been admitted for 2 weeks due to vomiting at another hospital. He had abdominal discomfort and nausea without abdominal pain when he visited the Gwangyang Sarang Hospital. Other than a distended abdomen and mild general abdominal tenderness, the results of physical examination were unremarkable. Abdominal CT revealed an approximately 9 cm thick walled hematoma at the anteroinferior site of the duodenal third portion. Upper endoscopy revealed stenosis of the third portion of the duodenum without mucosal lesions. The endoscope was not advanced through the narrowed duodenal lumen. A retroperitoneal hematoma was diagnosed, and his state was classified as subacute rather than acute based on the duration. The surgeon did not recommend surgical treatment. Urgent treatment was unnecessary; he was managed conservatively. The size of the hematoma decreased from 9.0 cm to 5.8 cm on the following CT. He could begin to eat food on the 26th admission day, and he was discharged on the 31st admission day. The hematoma disappeared entirely on the following CT. This paper describes a rare case of idiopathic retroperitoneal hematoma with a spontaneous resolution.

Strategy for Selective Printing of Gate Insulators Customized for Practical Application in Organic Integrated Devices

Direct drawing techniques have contributed to the ease of patterning soft electronic materials, which are the building blocks of analog and digital integrated circuits. In parallel with the printing of semiconductors and electrodes, selective deposition of gate insulators (GI) is an equally important factor in simplifying the fabrication of integrated devices, such as NAND and NOR gates, and memory devices. This study demonstrates the fabrication of six types of printed GI layers (high/low-k polymer and organic-inorganic hybrid material), which are utilized as GIs in organic field-effect transistors (OFETs), using the electrostatic-force-assisted dispensing printing technique. The selective printing of GIs on the gate electrodes enables us to develop practical integrated devices that go beyond unit OFET devices, exhibiting robust switching performances, non-destructive operations, and high gain values. Moreover, the flexible integrated devices fabricated using this technique exhibit excellent operational behavior. Therefore, this facile fabrication technique can pave a new path for the production of practical integrated device arrays for next-generation devices.

Aluminum Oxide Nanoparticle Films Deposited from a Nonthermal Plasma: Synthesis, Characterization, and Crystallization

Aluminum oxide, both in amorphous and crystalline forms, is a widely used inorganic ceramic material because of its chemical and structural properties. In this work, we synthesized amorphous aluminum oxide nanoparticles using a capacitively coupled nonthermal plasma utilizing trimethylaluminum and oxygen as precursors and studied their crystallization and phase transformation behavior through postsynthetic annealing. The use of two reactor geometries resulted in amorphous aluminum oxide nanoparticles with similar compositions but different sizes. Size tuning of these nanoparticles was achieved by varying the reactor pressure to produce amorphous aluminum oxide nanoparticles ranging from 6 to 22 nm. During postsynthetic annealing, powder samples of amorphous nanoparticles began to crystallize at 800 °C, forming crystalline θ and γ phase alumina. Their phase transformation behavior was found to be size-dependent in that powders of small 6 nm amorphous particles transformed to form phase-pure α-Al₂O₃ at 1100 °C, while powders of large 11 nm particles remained in the θ and γ phases. This phenomenon is attributed to the fast rate of densification and neck formation in small amorphous aluminum oxide particles.

Direct Printing of Asymmetric Electrodes for Improving Charge Injection/Extraction in Organic Electronics

Engineering the energy levels of organic conducting materials can be useful for developing high-performance organic field-effect transistors (OFETs), whose electrodes must be well controlled to facilitate easy charge carrier transport from the source to drain through an active channel. However, symmetric source and drain electrodes that have the same energy levels are inevitably unfavorable for either charge injection or charge extraction. In this study, asymmetric source and drain electrodes are simply prepared using the electrohydrodynamic (EHD)-jet printing technique after the careful work function engineering of organic conducting material composites. Two types of additives effectively tune the energy levels of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate-based composites. These solutions are alternately patterned using the EHD-jet printing process, where the use of an electric field makes fine jet control that enables to directly print asymmetric electrodes. The asymmetric combination of EHD-printed electrodes helps in obtaining advanced charge transport properties in p-type and n-type OFETs, as well as their organic complementary inverters. This strategy is believed to provide useful guidelines for the facile patterning of asymmetric electrodes, enabling the desirable properties of charge injection and extraction to be achieved in organic electronic devices.

Synthesis of Cyclopentadithiophene-Diketopyrrolopyrrole Donor-Acceptor Copolymers for High-Performance Nonvolatile Floating-Gate Memory Transistors with Long Retention Time

Organic flash memories that employ solution-processed polymer semiconductors preferentially require internal stability of their active channel layers. In this paper, a series of new donor-acceptor copolymers based on cyclopentadithiophene (CDT) and diketopyrrolopyrrole (DPP) are synthesized to obtain high performance and operational stability of nonvolatile floating-gate memory transistors with various additional donor units including thiophene, thiophene-vinylene-thiophene (CDT-DPP-TVT), selenophene, and selenophene-vinylene-selenophene. Detailed analyses on the photophysical, two-dimensional grazing incident X-ray diffraction, and bias stress stability are discussed, which reveal that the CDT-DPP-TVT exhibits excellent bias stress stability over 10⁵ s. To utilize the robust nature of CDT-DPP-TVT, floating-gate transistors are fabricated by embedding Au nanoparticles between Cytop layers as a charge storage site. The resulting memory devices reveal bistable current states with high on/off current ratio larger than 10⁴ and each state can be distinguished for more than 1 year, indicating a long retention time. Moreover, repetitive writing-reading-erasing-reading test clearly supports the reproducible memory operation with reversible and reliable electrical responses. All these results suggest that the internal stability of CDT-DPP-TVT makes this copolymer a promising material for application in reliable organic flash memory.

Efficient Debundling of Few-Walled Carbon Nanotubes by Wrapping with Donor-Acceptor Polymers for Improving Thermoelectric Properties

Organic thermoelectric (TE) materials have great potential as sustainable energy sources for powering flexible and wearable electronic devices via harvesting of human body heat. Recent advances in soluble conjugated polymer/carbon nanotube (CNT) composites have facilitated achievement of high TE power factors. However, the effects of conjugated polymers on the debundling and electrical percolation of CNTs and on the TE properties of their composites are not yet fully understood. Herein, we introduce a novel type of polymer/CNT composite composed of a donor-acceptor (D-A)-type polymer and few-walled CNTs (FWCNTs). Three kinds of D-A polymers are employed to disperse FWCNTs, and the photophysical, morphological, and TE properties of the resulting polymer/FWCNT composites are compared with those of composites composed of FWCNTs dispersed with conventional donor-only poly(3-hexylthiophene). The results reveal that the strong intermolecular interaction forces and high backbone planarity of the D-A polymers facilitate effective debundling of FWCNTs, which results in much smaller bundle sizes. Consequently, the D-A polymer/FWCNT composite films show superior electrical percolation and TE performances with improved power factors of up to 459 μW/mK². Finally, we demonstrate the feasibility of the D-A polymer/FWCNT composites for use in the fabrication of a flexible TE generator, which shows a maximum power output of 210 nW at a temperature gradient of 20 K.

Enhanced solvent resistance and electrical performance of electrohydrodynamic jet printed PEDOT:PSS composite patterns: effects of hardeners on the performance of organic thin-film transistors

Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonic acid) (PEDOT:PSS) is of great interest as a promising metal-free electrode material for future electronic devices. Several printing techniques have been developed to generate PEDOT:PSS patterns. In this study, we introduced a silicon-based hardener into PEDOT:PSS composites to prepare conductive ink for the purpose of fabricating solvent-resistant PEDOT:PSS composite patterns. Electrohydrodynamic (EHD) jet printing enabled the direct patterning of PEDOT:PSS and hardener composites that exhibited improved electrical conductivity and solvent resistance, which are advantageous properties for efficient charge injection when semiconductor materials are coated onto pre-deposited PEDOT:PSS composite electrodes. By using EHD jet printed PEDOT:PSS composites as source and drain electrodes, bottom-gate-bottom-contact organic thin-film transistors (OTFTs) were fabricated. The resulting OTFTs with PEDOT:PSS and hardener composite electrodes exhibited superior electrical performance compared to OTFTs with electrodes without hardener. Finally, OTFTs with both EHD jet printed electrodes and semiconductors were fabricated and analyzed.

High-Resolution, Fast, and Shape-Conformable Hydrogen Sensor Platform: Polymer Nanofiber Yarn Coupled with Nanograined Pd@Pt

We report a flexible hydrogen sensing platform based on a single-strand yarn consisting of high-density electrospun nanofibers, on which nanograined Pd or Pd@Pt is coated via yarn spinning followed by sputter deposition. In general, Pd undergoes a phase transition to PdH _x (α-PdH _x at [H₂] < 1% and β-PdH _x at [H₂] > 2%), in which H atoms act as electron scattering centers, thus increasing the resistance. In our system, the sensors exhibit switchable H₂ sensing behaviors, that is, (i) Δ R/ R₀ > 0 at [H₂] > 1% by the active electron scattering and (ii) Δ R/ R₀ < 0 at [H₂] < 1% derived from nanograined Pd effects. Due to high mechanical stability stemming from nanogranular morphologies of Pd, which is essential for enduring a huge volume expansion upon exposure to high-concentration H₂, we could obtain a wide concentration range (4-0.0001%) H₂ detection resolution. Moreover, an ultrathin Pt overlayer coated on Pd offers an accelerated H₂ detection capability based on effective gas dissociation and activation properties. Furthermore, by virtue of the core (thread)-shell (nanofiber yarn) scaffold, long cycling reliability and flexibility were achieved. This facile and low-cost yarn fabrication method offers the development of single-strand thread-type wearable chemiresistors that possess a high surface area and open porosity, facilitating gas diffusion and reaction.

A Quinacridone-Diphenylquinoxaline-Based Copolymer for Organic Field-Effect Transistors

In this work, we characterized poly(quinacridone-diphenylquinoxaline) (PQCTQx). PQCTQx was synthesized by a Suzuki coupling reaction and the synthesized PQCTQx was used as a polymeric semiconducting material in organic field-effect transistors (OFETs) to research the potential of using quinacridone derivatives. The measured field-effect mobility of the pristine PQCTQx film was 6.1 × 10⁻³ cm²/(V·s). A PQCTQx film heat-treated at 150 °C exhibited good field-effect performances with a hole mobility of 1.2 × 10⁻² cm²/(V·s). The improved OFET behaviors resulting from the mild thermal treatment was attributed to improved packing of the molecules in the film, as determined using X-ray diffraction, and to decreased channel resistance.

Heterogeneous Metal Oxide-Graphene Thorn-Bush Single Fiber as a Freestanding Chemiresistor

The development of freestanding fiber-type chemiresistors, having high integration ability with various portable electronics including smart clothing systems, is highly demanding for the next-generation wearable sensing platforms. However, critical challenges stemming from the irreversible chemical sensing kinetics and weak reliability of the freestanding fiber-type chemiresistor hinder their practical use. In this work, for the first time, we report on the potential suitability of the freestanding and ultraporous reduced graphene oxide fiber functionalized with WO₃ nanorods (porous WO₃ NRs-RGO composite fiber) as a sensitive nitrogen dioxide (NO₂) detector. By employing a tunicate cellulose nanofiber (TCNF), which is a unique animal-type cellulose, the numerous mesopores are formed on a wet-spun TCNF-GO composite fiber, unlike a bare GO fiber with dense surface structure. More interestingly, due to the superior wettability of TCNF, the aqueous tungsten precursor is uniformly adsorbed on an ultraporous TCNF-GO fiber, and subsequent heat treatment results in the thermal reduction of a TCNF-GO fiber and hierarchical growth of WO₃ NRs perpendicular to the porous RGO fiber (porous WO₃ NRs-RGO fiber). The freestanding porous WO₃ NRs-RGO fiber shows a notable response to 1 ppm NO₂. Furthermore, we successfully demonstrate reversible NO₂ sensing characteristics of the porous WO₃ NRs-RGO fiber, which is integrated on a wrist-type wearable sensing device.

Bio-inspired heterogeneous sensitization of bimetal oxides on SnO2 scaffolds for unparalleled formaldehyde detection

NiO/Fe₂O₃–SnO₂ fiber-in-tubes showed remarkably enhanced sensing properties and superior cross-sensitivity toward sub-ppm levels of formaldehyde.

Surface Modification of CdSe Quantum-Dot Floating Gates for Advancing Light-Erasable Organic Field-Effect Transistor Memories

Photoresponsive transistor memories that can be erased using light-only bias are of significant interest owing to their convenient elimination of stored data for information delivery. Herein, we suggest a strategy to improve light-erasable organic transistor memories, which enables fast "photoinduced recovery" under low-intensity light. CdSe quantum dots (QDs) whose surfaces are covered with three different organic molecules are introduced as photoactive floating-gate interlayers in organic transistor memories. We determine that CdSe QDs capped or surface-modified with small molecular ligands lead to efficient hole diffusion from the QDs to the conducting channel during "photoinduced recovery", resulting in faster erasing times. In particular, the memories with QDs surface-modified with fluorinated molecules function as normally-ON type transistor memories with nondestructive operation. These memories exhibit high memory ratios over 10⁵ between OFF and ON bistable current states for over 10 000 s and good dynamic switching behavior with voltage-driven programming processes and light-assisted erasing processes within 1 s. Our study provides a useful guideline for designing photoactive floating-gate materials to achieve desirable properties of light-erasable organic transistor memories.

Chitosan-templated Pt nanocatalyst loaded mesoporous SnO2 nanofibers: a superior chemiresistor toward acetone molecules

In this work, we introduce a chitosan-Pt complex (CS-Pt) as an effective template for catalytic Pt sensitization and creation of abundant mesopores in SnO2 nanofibers (NFs). The Pt particles encapsulated by the CS exhibit ultrasmall size (∼2.6 nm) and high dispersion characteristics due to repulsion between CS molecules. By combining CS-Pt with electrospinning, mesoporous SnO2 NFs uniformly functionalized with the Pt catalyst (CS-Pt@SnO2 NFs) are synthesized. Particularly, numerous mesopores with diameters of ∼20 nm form through the decomposition of CS, while a small SnO2 grain size (14.32 nm) is achieved by the pinning effect of CS. It is observed that CS-Pt@SnO2 NFs exhibit outstanding response (Rair/Rgas = 141.92 at 5 ppm), excellent selectivity, stability, and fast response (12 s)/recovery (44 s) speed toward 1 ppm of acetone at 350 °C and high humidity (90% RH). In addition, by applying an exponential fitting tool to experimental response values toward 0.1-5 ppm of acetone, it is estimated that CS-Pt@SnO2 NFs can detect 5 ppb of acetone with a notable response (Rair/Rgas = 2.9). Furthermore, the sensor array based on CS-Pt@SnO2 NFs, CS-driven SnO2 NFs, polyol-Pt loaded SnO2 NFs, and dense SnO2 NFs obviously classifies simulated diabetic breath and healthy human breath by using a pattern recognition tool. These results clearly demonstrate that mesoporous SnO2 NFs, particularly functionalized with CS-Pt templated nanocatalysts, open up a new class of sensing layers offering high sensitivity and selectivity.

Nanoscale PtO2 Catalysts-Loaded SnO2 Multichannel Nanofibers toward Highly Sensitive Acetone Sensor

PtO₂ nanocatalysts-loaded SnO₂ multichannel nanofibers (PtO₂-SnO₂ MCNFs) were synthesized by single-spinneret electrospinning combined with apoferritin and two immiscible polymers, i.e., poly(vinylpyrrolidone) and polyacrylonitrile. The apoferritin, which can encapsulate nanoparticles within a small inner cavity (8 nm), was used as a catalyst loading template for an effective functionalization of the PtO₂ catalysts. Taking advantage of the multichannel structure with a high porosity, effective activation of catalysts on both interior and exterior site of MCNFs was realized. As a result, under high humidity condition (95% RH), PtO₂-SnO₂ MCNFs exhibited a remarkably high acetone response (R_air/R_gas = 194.15) toward 5 ppm acetone gases, superior selectivity to acetone molecules among various interfering gas species, and excellent stability during 30 cycles of response and recovery toward 1 ppm acetone gases. In this work, we first demonstrate the high suitability of multichannel semiconducting metal oxides structure functionalized by apoferritin-encapsulated catalytic nanoparticles as highly sensitive and selective gas-sensing layer.

The effect of surfactants on electrohydrodynamic jet printing and the performance of organic field-effect transistors

In this article, we report on the direct writing of multi-walled carbon nanotube (MWCNT) composite inks based on three different surfactants via the electrohydrodynamic (EHD) jet printing technique.

Integration of piezo-capacitive and piezo-electric nanoweb based pressure sensors for imaging of static and dynamic pressure distribution

Recently, highly flexible and soft pressure distribution imaging sensor is in great demand for tactile sensing, gait analysis, ubiquitous life-care based on activity recognition, and therapeutics. In this study, we integrate the piezo-capacitive and piezo-electric nanowebs with the conductive fabric sheets for detecting static and dynamic pressure distributions on a large sensing area. Electrical impedance tomography (EIT) and electric source imaging are applied for reconstructing pressure distribution images from measured current-voltage data on the boundary of the hybrid fabric sensor. We evaluated the piezo-capacitive nanoweb sensor, piezo-electric nanoweb sensor, and hybrid fabric sensor. The results show the feasibility of static and dynamic pressure distribution imaging from the boundary measurements of the fabric sensors.

Photoinduced Recovery of Organic Transistor Memories with Photoactive Floating-Gate Interlayers

Optical memories based on photoresponsive organic field-effect transistors (OFETs) are of great interest due to their unique applications, such as multibit storage memories and flexible imaging circuits. Most studies of OFET-type memories have focused on the photoresponsive active channels, but more useful functions can be additionally given to the devices by using floating gates that can absorb light. In this case, effects of photoirradiation on photoactive floating-gate layers need to be fully understood. Herein, we studied the photoinduced erasing effects of floating-gate interlayers on the electrical responses of OFET-type memories and considered the possible mechanisms. Polymer/C₆₀ composites were inserted between pentacene and SiO₂ to form photoresponsive floating-gate interlayers in transistor memory. When exposed to light, C₆₀ generated excitons, and these photoexcited carriers contributed to the elimination of trapped charge carriers, which resulted in the recovery of OFET performance. Such memory devices exhibited bistable current states controlled with voltage-driven programming and light-driven erasure. Furthermore, these devices maintained their charge-storing properties over 10 000 s. This proof-of-concept study is expected to open up new avenues in information technology for the development of organic memories that exhibit photoinduced recovery over a wide range of wavelengths of light when combined with appropriate photoactive floating-gate materials.

Analysis and comparison of the cost-effectiveness of statins according to the baseline low-density lipoprotein cholesterol level in Korea

WHAT IS KNOWN AND OBJECTIVE

There are a few Korean studies on the economics of statins based on reduction in low-density lipoprotein cholesterol (LDL-C) data from other countries. This study aimed to analyse and compare the cost-effectiveness of statins according to the baseline LDL-C level in Korea.

METHODS

Between January 2009 and December 2015, the data of patients who were prescribed statins for the first time were extracted from electronic medical records. We performed a cost-effectiveness analysis (CEA) based on the LDL-C reduction rate (CEA-RR) and target achievement rate.

RESULTS AND DISCUSSION

Among high-intensity statins, the CEA-RR value of rosuvastatin (20 mg) was significantly lower than that of atorvastatin (40 mg) at all baseline LDL-C levels, except levels of 160-189 mg/dL. Additionally, at baseline LDL-C levels of 130-159 mg/dL, the CEA-RR value of rosuvastatin (20 mg) was three times lower than that of atorvastatin (40 mg) (9·1 ± 2·5 $/% vs. 31·7 ± 15·0 $/%, P < 0·001). Among moderate-to-low-intensity statins, rosuvastatin (5 mg) showed the lowest CEA-RR value (4·0 ± 0·6 $/%), and the value significantly increased for pitavastatin (2 mg) (8·0 ± 0·6 $/%), atorvastatin (10 mg) (9·5 ± 0·5 $/%), simvastatin (10·8 ± 1·1 $/%) and pravastatin (40 mg) (11·5 ± 0·9 $/%) in order (P < 0·0001). On changing from atorvastatin (10 mg) to atorvastatin (20 mg), the additional yearly cost was 16·0 and additional CEA-RR value was 2·74 $/%. On the other hand, on changing from atorvastatin (10 mg) to rosuvastatin (10 mg), the additional yearly cost was -16·3 and additional CEA-RR value was -1·8 $/%.

WHAT IS NEW AND CONCLUSION

We successfully compared the cost-effectiveness of statins according to the baseline LDL-C level in Korea. It is expected that our findings will help clinical decision-making with regard to statin prescription, and this will help reduce national medical expenditure.

Abstract P6-05-05: The expression of lysyl oxidase and fibrotic focus is related to inflammation in breast cancer

Background: Lysyl oxidase (LOX) is an extracellular matrix enzyme that catalyzes the

cross-linking of collagens or elastin. Our hypothesis is that LOX contributes to the formation

of a fibrotic focus (FF), which is related to inflammation in breast carcinogenesis.

In this study, we analyzed the association between the expression LOXs and FF, and

investigated prognostic significance in breast cancer.

Methods: Tissue microarrarys were constructed from the specimens of 444 patients

with primary invasive breast cancer. Immunohistochemical staining for LOX, LOXlike

(LOXL)-, LOXL-2 and LOXL-3 was performed. The status of FF within the tumor

was assessed. The number of CD4+ T cells, CD8+ T cells, CD68+ macrophages was

counted, and intratumoral and peritumoral lymphocyte infiltration were evaluated.

The clinicopathologic characteristics of the patients were analyzed.

Result: The percentage of positive FF was 39.2% and positive rate of LOX expression

was 50% in primary breast cancer tissues. FF was found to be significantly associated

with intratumoral and peritumoral inflammation, lymph node metastasis, high histologic

grade, larger tumor size. LOX was associated with intratumoral and peritumoral

inflammation, CD8+ T cells and menopausal status. LOXL-3 was significantly associated

with positive expression of ER and PR, and molecular subtype.

Conclusions: FF and the expression of LOX were associated with inflammation in

breast cancer in this study. Our results suggest that LOXs may contribute to the formation

of a FF indirectly in relation with inflammation in breast cancer. Further studies

are needed to clarify the role of LOXs, FF and inflammation in tumorigenesis and

prognostic value of them in breast cancer.

Citation Format: Park SH, Jeong YJ, Bong JG, Oh HK. The expression of lysyl oxidase and fibrotic focus is related to inflammation in breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P6-05-05.

Comparative analysis of the efficacy of omega-3 fatty acids for hypertriglyceridaemia management in Korea

WHAT IS KNOWN AND OBJECTIVE

This study aimed to compare the ability of statin monotherapy (ST group), omega-3 fatty acid monotherapy (OM_A group) and combination therapy with omega-3 fatty acids and a statin (OM_S group), to reduce triglyceride (TG) levels in patients with hypertriglyceridaemia.

METHODS

In this retrospective cohort study, we extracted data from the electronic medical records of patients initially prescribed either a statin or omega-3 fatty acids between January, 2009 and December, 2013. We performed a comparative analysis of the change in cholesterol levels between baseline and an average of 3 months later.

RESULTS AND DISCUSSION

Data were extracted for 2071 patients. The average daily eicosapentaenoic acid (EPA) ethyl ester and docosahexaenoic acid (DHA) ethyl ester intake was 1689 mg, and 79-86% of the OM_A and OM_S groups were prescribed two omega-3 fatty acid capsules. At a baseline TG level of between 200 and 500 mg/dL, TG levels were reduced by 16 ± 2·8% in the ST group, 28 ± 2·8% in the OM_A group and 29 ± 2·3% in the OM_S group (P = 0·001 for ST group vs. OM_A and OM_S groups), with no difference between the OM_A and OM_S groups. At a baseline TG level ≥500 mg/dL, there was no difference in TG level reduction between the three groups (54 ± 7·3%, 55·8 ± 3·5% and 51·8 ± 6·8%, respectively, P = 0·851).

WHAT IS NEW AND CONCLUSION

Although omega-3 fatty acids are not considered the primary medication for hypertriglyceridaemia, the prescription of omega-3 fatty acids is justifiable if reduction in TG levels is judged to be necessary.

Photo-Patternable ZnO Thin Films Based on Cross-Linked Zinc Acrylate for Organic/Inorganic Hybrid Complementary Inverters

Complementary inverters consisting of p-type organic and n-type metal oxide semiconductors have received considerable attention as key elements for realizing low-cost and large-area future electronics. Solution-processed ZnO thin-film transistors (TFTs) have great potential for use in hybrid complementary inverters as n-type load transistors because of the low cost of their fabrication process and natural abundance of active materials. The integration of a single ZnO TFT into an inverter requires the development of a simple patterning method as an alternative to conventional time-consuming and complicated photolithography techniques. In this study, we used a photocurable polymer precursor, zinc acrylate (or zinc diacrylate, ZDA), to conveniently fabricate photopatternable ZnO thin films for use as the active layers of n-type ZnO TFTs. UV-irradiated ZDA thin films became insoluble in developing solvent as the acrylate moiety photo-cross-linked; therefore, we were able to successfully photopattern solution-processed ZDA thin films using UV light. We studied the effects of addition of a tiny amount of indium dopant on the transistor characteristics of the photopatterned ZnO thin films and demonstrated low-voltage operation of the ZnO TFTs within ±3 V by utilizing Al2O3/TiO2 laminate thin films or ion-gels as gate dielectrics. By combining the ZnO TFTs with p-type pentacene TFTs, we successfully fabricated organic/inorganic hybrid complementary inverters using solution-processed and photopatterned ZnO TFTs.

Optimization of Al2O3/TiO2 nanolaminate thin films prepared with different oxide ratios, for use in organic light-emitting diode encapsulation, via plasma-enhanced atomic layer deposition

The shelf-life of the OLED devices passivated with and without PEALD-based films at 60 °C and 90% RH.

The Factors Associated With the Successful Outcomes of Percutaneous Disc Decompression in Patients With Lumbar Herniated Nucleus Pulposus

Objective

To determine clinical and radiological factors that predict the successful outcome of percutaneous disc decompression (PDD) in patients with lumbar herniated nucleus pulposus (HNP).

Methods

We retrospectively reviewed the clinical and radiological features of patients who underwent lumbar PDD from April 2009 to March 2013. Sixty-nine patients with lumbar HNP were studied. Clinical outcome was assessed by the visual analogue scale (VAS) and the Oswestry Disability Index (ODI). Multivariate logistic regression analysis was performed to assess relationship among clinical and radiological factors and the successful outcome of the PDD.

Results

The VAS and the ODI decreased significantly at 1 year follow-up (p<0.01). One year after PDD, the reduction of the VAS (ΔVAS) was significantly greater in the patients with pain for <6 months (p=0.03) and subarticular HNP (p=0.015). The reduction of the ODI (ΔODI) was significantly greater in the patients with high intensity zone (p=0.04). Multivariate logistic regression analysis revealed the following 5 factors that were associated with the successful outcome after PDD: pain duration for <6 months (odds ratio [OR]=14.036; p=0.006), positive straight leg raising test (OR=8.425, p=0.014), the extruded HNP (OR=0.106, p=0.04), the sequestrated HNP (OR=0.037, p=0.026), and the subarticular HNP (OR=10.876, p=0.012).

Conclusion

PDD provided significant improvement of pain and disability of patients. The results of the analysis indicated that the duration of pain <6 months, positive straight leg raising test, the subarticular HNP, and the protruded HNP were predicting factors associated with the successful response of PDD in patients with lumbar HNP.

Reduced Water Vapor Transmission Rate of Graphene Gas Barrier Films for Flexible Organic Field-Effect Transistors

Preventing reactive gas species such as oxygen or water is important to ensure the stability and durability of organic electronics. Although inorganic materials have been predominantly employed as the protective layers, their poor mechanical property has hindered the practical application to flexible electronics. The densely packed hexagonal lattice of carbon atoms in graphene does not allow the transmission of small gas molecules. In addition, its outstanding mechanical flexibility and optical transmittance are expected to be useful to overcome the current mechanical limit of the inorganic materials. In this paper, we reported the measurement of the water vapor transmission rate (WVTR) through the 6-layer 10 × 10 cm(2) large-area graphene films synthesized by chemical vapor deposition (CVD). The WVTR was measured to be as low as 10(-4) g/m(2)·day initially, and stabilized at ∼0.48 g/m(2)·day, which corresponds to 7 times reduction in WVTR compared to bare polymer substrates. We also showed that the graphene-passivated organic field-effect transistors (OFETs) exhibited excellent environmental stability as well as a prolonged lifetime even after 500 bending cycles with strain of 2.3%. We expect that our results would be a good reference showing the graphene's potential as gas barriers for organic electronics.

Solution-processed n-type fullerene field-effect transistors prepared using CVD-grown graphene electrodes: improving performance with thermal annealing

Solution-processed organic field effect transistors (OFETs) have generated significant interest as key elements for use in all-organic electronic applications aimed at realizing low-cost, lightweight, and flexible devices.

Directly drawn poly(3-hexylthiophene) field-effect transistors by electrohydrodynamic jet printing: improving performance with surface modification

In this study, direct micropatterning lines of poly(3-hexylthiophene) (P3HT) without any polymer binder were prepared by electrohydrodynamic jet printing to form organic field-effect transistors (OFETs). We controlled the dielectric surface by introducing self-assembled monolayers and polymer thin films to investigate the effect of surface modifications on the characteristics of printed P3HT lines and electrical performances of the OFETs. The morphology of the printed P3HT lines depended on the surface energy and type of substrate. The resulting OFETs exhibited high performance on octadecyltrichlorosilane-modified substrates, which was comparable to that of other printed P3HT OFETs. In order to realize the commercialization of the OFETs, we also fabricated a large-area transistor array, including 100 OFETs and low-operating-voltage flexible OFETs.

Highly stretchable resistive pressure sensors using a conductive elastomeric composite on a micropyramid array

A stretchable resistive pressure sensor is achieved by coating a compressible substrate with a highly stretchable electrode. The substrate contains an array of microscale pyramidal features, and the electrode comprises a polymer composite. When the pressure-induced geometrical change experienced by the electrode is maximized at 40% elongation, a sensitivity of 10.3 kPa(-1) is achieved.

High-performance organic complementary inverters using monolayer graphene electrodes

Chemical vapor deposition-grown graphene has been an attractive electrode material for organic electronic devices, such as organic field-effect transistors (OFETs), because it is highly conductive and provides good oxidation and thermal stability properties. However, it still remains a challenge to demonstrate organic complementary circuits using graphene electrodes because of the relatively poor performance of n-type OFETs. Here, we report the development of high-performance organic complementary inverters using graphene as source/drain electrodes and N, N'-ditridecyl-3,4,9,10-perylenetetracarboxylic diimide (PTCDI-C13) and pentacene as n- and p-type organic semiconductors, respectively. Graphene electrodes were n-doped via the formation of NH2-terminated self-assembled monolayers that lowered the work function and the electron injection barrier between the graphene and PTCDI-C13. Thermal annealing improved the molecular packing among PTCDI-C13 groups on the graphene surface, thereby increasing the crystallinity and grain size. The thermally annealed PTCDI-C13 OFETs prepared using n-doped graphene electrodes exhibited a good field-effect mobility of up to 0.43 cm2/(V s), which was comparable to the values obtained from other p-type pentacene OFETs. By integrating p- and n-type OFETs, we successfully fabricated organic complementary inverters that exhibited highly symmetric operation with an excellent voltage gain of up to 124 and good noise margin.

Al2O3/TiO2 nanolaminate thin film encapsulation for organic thin film transistors via plasma-enhanced atomic layer deposition

Organic electronic devices require a passivation layer that protects the active layers from moisture and oxygen because most organic materials are very sensitive to such gases. Passivation films for the encapsulation of organic electronic devices need excellent stability and mechanical properties. Although Al2O3 films obtained with plasma enhanced atomic layer deposition (PEALD) have been tested as passivation layers because of their excellent gas barrier properties, amorphous Al2O3 films are significantly corroded by water. In this study, we examined the deformation of PEALD Al2O3 films when immersed in water and attempted to fabricate a corrosion-resistant passivation film by using a PEALD-based Al2O3/TiO2 nanolamination (NL) technique. Our Al2O3/TiO2 NL films were found to exhibit excellent water anticorrosion and low gas permeation and require only low-temperature processing (<100 °C). Organic thin film transistors with excellent air-stability (52 days under high humidity (a relative humidity of 90% and a temperature of 38 °C)) were fabricated.

Predictors for the progression of geographic atrophy in patients with age-related macular degeneration: fundus autofluorescence study with modified fundus camera

PURPOSE

We examined the association between abnormal fundus autofluorescence (FAF) features on images obtained by a modified fundus camera (mFC) and geographic atrophy (GA) progression in patients with age-related macular degeneration (AMD).

METHODS

Serial FAF images of 131 eyes from 131 patients with GA were included in the study. All FAF images were obtained with an mFC (excitation, ∼ 500-610 nm; emission, ∼ 675-715 nm). The GA area was quantified at baseline and 1 year later using a customized segmentation program. The yearly GA enlargement rate was then calculated. Abnormal FAF patterns in the junctional zone of GA were classified as None or Minimal change, Focal, Patchy, Banded, or Diffuse according to previously published classification based on confocal scanning laser ophthalmoscopy (cSLO). The relationship between GA enlargement and abnormal FAF was evaluated.

RESULTS

The mean rate of GA enlargement was the fastest in eyes with Diffuse pattern (1.74 mm(2) per year), followed by eyes with the Banded pattern (1.69 mm(2) per year). Binary logistic regression analysis revealed that eyes with the Banded and Diffuse pattern had significantly higher risk for GA enlargement compared with eyes with the other patterns.

CONCLUSIONS

FAF image obtained by mFC appears to be acceptable for evaluating GA in accordance with an established cSLO-based classification. Eyes with the Banded or the Diffuse patterns of abnormal FAF at baseline indicate a high risk for GA progression. Identifying patients at high risk for GA progression using an mFC is broadly available method that can provide additional information to help predict disease course.

Abstract P2-06-05: Association of promoter methylation status of the FHIT gene and Fhit expression with HER2/neu status in breast cancer

Purpose: Aberrant DNA methylation has been recognized to contribute to breast carcinogenesis, and promoter hypermethylation of many tumor suppressor genes has been correlated with decreased gene expression. The fragile histidine triad (FHIT) gene is a putative tumor suppressor gene in breast and other cancers, and loss of Fhit expression has been observed in breast cancers. The aim of this study was to evaluate the association between methylation of the FHIT gene and its expression in breast cancer, and to investigate whether methylation and expression of the FHIT gene would correlate with clinicopathological characteristics in relation to human epidermal growth factor receptor 2 (HER2) status.

Methods: Pyrosequencing of bisulfite treated DNA was performed to study the methylation status of the FHIT gene in 60 breast cancer samples from Korean women obtained at Daegu Catholic University Hospital. We examined the expression of FHIT using tissue microarrays by immunohistochemical staining. Association between the methylation status of the FHIT gene and its expression was analyzed, and the relationship between the FHIT expression and the clinicopathological characteristics of the patients was evaluated.

Results: FHIT methylation was detected in 96.7% and positive expression rate of Fhit was 87.3% of the patients. The mean methylation level of the FHIT gene was associated with intratumoral inflammation. Methylation level of the FHIT gene had no significant differences according to molecular subtypes. Loss of Fhit expression was associated with large tumor size, basal-like subtype and positive expression of EGFR. In HER2-negative breast cancers, loss of Fhit expression was significantly associated with tumor size, estrogen receptor status and Ki-67 proliferation index. There was no significant correlation between methylation of the FHIT gene and its expression in this study.

Conslusion: Our study revealed that loss of Fhit expression in breast cancer is associated with poor prognostic features, although there is no significance association between the FHIT gene methylation and Fhit expression. We found that in HER2-negatvie breast cancers, loss of Fhit expression was associated with poor prognostic features. These results support the possibility of potential complementation between HER2 and the Fhit pathway. The clinical significance of our findings needs to be further evaluated in larger cohorts with longer follow-up.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-06-05.

Enhanced graphitization of carbon around carbon nanotubes during the formation of carbon nanotube/graphite composites by pyrolysis of carbon nanotube/polyaniline composites

The carbon nanotubes (CNTs) are actively applied to the reinforcements for composite materials during last decade. One of the attempts is development of CNT/Carbon composites. Although there are some reports on the enhancement of mechanical properties by addition of CNTs in carbon or carbon fiber, it is far below the expectation. Considering the microstructure of carbon materials such as carbon fiber, the properties of them can be modified and enhanced by control of graphitization and alignment of graphene planes. In this study, enhanced graphitization of carbon has been observed the vicinity of CNTs during the pyrolysis of CNT/Polyaniline composites. As a result, novel types of composite, consisting of treading CNTs and coated graphite, can be fabricated. High-resolution transmission electron microscopy revealed a specific orientation relationship between the graphene layers and the CNTs, with an angle of 110 degrees between the layers and the CNT axis. The possibility of graphene alignment control in the carbon by the addition of CNTs is demonstrated.

Comparison of chest digital tomosynthesis and chest radiography for detection of asbestos-related pleuropulmonary disease

AIM

To compare chest digital tomosynthesis (DTS) with digital radiography for the detection of asbestos-related pleuropulmonary disease.

MATERIALS AND METHODS

The institutional review board approved this study and all participants gave informed consent. Forty-five participants with a history of asbestos exposure were examined with DTS and radiography. Low-dose multidetector computed tomography (CT) in the prone position served as the reference. Two observers evaluated all images for the presence of pleural abnormalities and asbestosis. Interobserver agreement was analysed by using the k statistic. Diagnostic performance of the two imaging methods was compared using McNemar's test.

RESULTS

Interobserver agreement regarding DTS findings was moderate to very good (k = 0.544-0.846) and superior to the radiographic findings (k = 0.236-1.000). Overall, the diagnostic accuracy of DTS for the lesion detection was significantly better than with radiography (all p < 0.05, except that for the comparison of diagnostic accuracy of DTS versus radiographic detection of left diaphragmatic plaques and asbestosis). DTS was more sensitive than radiography for the detection of asbestosis (82% versus 27%, p = 0.031).

CONCLUSION

DTS is more accurate than radiography in the detection of pleural plaques and more sensitive than radiography in the detection of asbestosis. Interobserver agreements with respect to the DTS findings were superior to the radiographic findings.