Association of Body Composition Changes with the Development of Diabetes Mellitus: A Nation-Wide Population Study.

Background: We investigated the association between body composition changes and new-onset diabetes mellitus (DM) development according to the body mass index (BMI) in a longitudinal setting in the general Korean population. Methods: From 2010 to 2011 (1st) and 2012 to 2013 (2nd), we included 1,607,508 stratified random sample participants without DM from the National Health Insurance Service-Health Screening dataset of Korean. The predicted appendicular skeletal muscle mass index (pASMMI), body fat mass index (pBFMI), and lean body mass index (pLBMI) were calculated using pre-validated anthropometric prediction equations. A prediction equation was constructed by combining age, weight, height, waist circumference, serum creatinine levels, alcohol consumption status, physical activity, and smoking history as variables affecting body composition. Results: Decreased pASMMI (men: hazard ratio [HR], 0.866; 95% confidence interval [CI], 0.830 to 0.903; P<0.001; women: HR, 0.748; 95% CI, 0.635 to 0.881; P<0.001), decreased pLBMI (men: HR, 0.931; 95% CI, 0.912 to 0.952; P<0.001; women: HR, 0.906; 95% CI, 0.856 to 0.959; P=0.007), and increased pBFMI (men: HR, 1.073; 95% CI, 1.050 to 1.096; P<0.001; women: HR, 1.114; 95% CI, 1.047 to 1.186; P=0.007) correlated with the development of new-onset DM. Notably, only in the overweight and obese BMI categories, decreases in pASMMI and pLBMI and increases in pBFMI associated with new-onset DM, regardless of gender. Conclusion: Decreased pASMMI and pLBMI, and increased pBFMI with excess fat accumulation may enhance the risk of newonset DM. Therefore, appropriate changes in body composition can help prevent new-onset DM.

Impact of Renal Function on Short-Term Outcome After Reperfusion Therapy in Patients With Ischemic Stroke.

BACKGROUND: A high and low estimated glomerular filtration rate (eGFR) could affect outcomes after reperfusion therapy for ischemic stroke. This study aimed to determine whether renal function based on eGFR affects mortality risk in patients with ischemic stroke within 6 months following reperfusion therapy. METHODS: This prospective registry-based cohort study included 2266 patients who received reperfusion therapy between January 2000 and September 2019 and were registered in the SECRET (Selection Criteria in Endovascular Thrombectomy and Thrombolytic Therapy) study or the Yonsei Stroke Cohort. A high and low eGFR were based on the Chronic Kidney Disease Epidemiology Collaboration equation and defined, respectively, as the 5th and 95th percentiles of age- and sex-specific eGFR. Occurrence of death within 6 months was compared among the groups according to their eGFR such as low, normal, or high eGFR. RESULTS: Of the 2266 patients, 2051 (90.5%) had a normal eGFR, 110 (4.9%) a low eGFR, and 105 (4.6%) a high eGFR. Patients with high eGFR were younger or less likely to have hypertension, diabetes, or atrial fibrillation than the other groups. Active cancer was more prevalent in the high-eGFR group. During the 6-month follow-up, there were 24 deaths (22.9%) in the high-eGFR group, 37 (33.6%) in the low-eGFR group, and 237 (11.6%) in the normal-eGFR group. After adjusting for variables with P<0.10 in the univariable analysis, 6-month mortality was independently associated with high eGFR (hazard ratio, 2.22 [95% CI, 1.36-3.62]; P=0.001) and low eGFR (HR, 2.29 [95% CI, 1.41-3.72]; P=0.001). These associations persisted regardless of treatment modality or various baseline characteristics. CONCLUSIONS: High eGFR as well as low eGFR were independently associated with 6-month mortality after reperfusion therapy. Kidney function could be considered a prognostic factor in patients with ischemic stroke after reperfusion therapy.

Efficient and Stable Fiber Dye-Sensitized Solar Cells Based on Solid-State Li-TFSI Electrolytes with 4-Oxo-TEMPO Derivatives.

Fiber-shaped dye-sensitized solar cells (FDSSCs) with flexibility, weavablity, and wearability have attracted intense scientific interest and development in recent years due to their low cost, simple fabrication, and environmentally friendly operation. Since the Grätzel group used the organic radical 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) as the redox system in dye-sensitized solar cells (DSSCs) in 2008, TEMPO has been utilized as an electrolyte to further improve power conversion efficiency (PCE) of solar cells. Hence, the TEMPO with high catalyst oxidant characteristics was developed as a hybrid solid-state electrolyte having high conductivity and stability structure by being integrated with a lithium bis(trifluoromethanesulfonyl)imide (Li-TFSI) film for FDSSCs. The optimized 4-Oxo TEMPO (OX) based solid-state FDSSC (SS-FDSSC) showed the PCE of up to 6%, which was improved by 34.2% compared to that of the reference device with 4.47%. The OX-enhanced SS-FDSSCs reduced a series resistance (Rs) resulting in effective electron extraction with improved short-circuit current density (JSC), while increasing a shunt resistance (Rsh) to prevent the recombination of photo-excited electrons. The result is an improvement in a fill factor (FF) and consequently a higher value for the PCE.

Achieving Cycling Stability in Anode of Lithium-Ion Batteries with Silicon-Embedded Titanium Oxynitride Microsphere.

Surface coating approaches for silicon (Si) have demonstrated potential for use as anodes in lithium-ion batteries (LIBs) to address the large volume change and low conductivity of Si. However, the practical application of these approaches remains a challenge because they do not effectively accommodate the pulverization of Si during cycling or require complex processes. Herein, Si-embedded titanium oxynitride (Si-TiON) was proposed and successfully fabricated using a spray-drying process. TiON can be uniformly coated on the Si surface via self-assembly, which can enhance the Si utilization and electrode stability. This is because TiON exhibits high mechanical strength and electrical conductivity, allowing it to act as a rigid and electrically conductive matrix. As a result, the Si-TiON electrodes delivered an initial reversible capacity of 1663 mA h g-1 with remarkably enhanced capacity retention and rate performance.

Improved Light Harvesting of Fiber-Shaped Dye-Sensitized Solar Cells by Using a Bacteriophage Doping Method.

Fiber-shaped solar cells (FSCs) with flexibility, wearability, and wearability have emerged as a topic of intensive interest and development in recent years. Although the development of this material is still in its early stages, bacteriophage-metallic nanostructures, which exhibit prominent localized surface plasmon resonance (LSPR) properties, are one such material that has been utilized to further improve the power conversion efficiency (PCE) of solar cells. This study confirmed that fiber-shaped dye-sensitized solar cells (FDSSCs) enhanced by silver nanoparticles-embedded M13 bacteriophage (Ag@M13) can be developed as solar cell devices with better PCE than the solar cells without them. The PCE of FDSSCs was improved by adding the Ag@M13 into an iodine species (I-/I3-) based electrolyte, which is used for redox couple reactions. The optimized Ag@M13 enhanced FDSSC showed a PCE of up to 5.80%, which was improved by 16.7% compared to that of the reference device with 4.97%.

Environmentally Compatible Lead-Free Perovskite Solar Cells and Their Potential as Light Harvesters in Energy Storage Systems.

Next-generation renewable energy sources and perovskite solar cells have revolutionised photovoltaics research and the photovoltaic industry. However, the presence of toxic lead in perovskite solar cells hampers their commercialisation. Lead-free tin-based perovskite solar cells are a potential alternative solution to this problem; however, numerous technological issues must be addressed before the efficiency and stability of tin-based perovskite solar cells can match those of lead-based perovskite solar cells. This report summarizes the development of lead-free tin-based perovskite solar cells from their conception to the most recent improvements. Further, the methods by which the issue of the oxidation of tin perovskites has been resolved, thereby enhancing the device performance and stability, are discussed in chronological order. In addition, the potential of lead-free tin-based perovskite solar cells in energy storage systems, that is, when they are integrated with batteries, is examined. Finally, we propose a research direction for tin-based perovskite solar cells in the context of battery applications.

Printable Free-Standing Hybrid Graphene/Dry-Spun Carbon Nanotube Films as Multifunctional Electrodes for Highly Stable Perovskite Solar Cells.

Perovskite solar cells (PSCs) have attracted immense attention owing to their outstanding power conversion efficiency (PCE). However, their counter electrodes are commonly produced by evaporating metals, such as Ag and Au, under high vacuum conditions, which make the PSCs costly, thereby limiting their large-scale production. In this study, a free-standing hybrid graphene/carbon nanotube film was carefully designed to replace noble metal PSC counter electrodes to reduce the cost and increase the stability of PSCs. A highly conductive and stable hybrid carbon thin film can be easily transferred to the various desired substrates by a simple rolling process. The PSCs with hybrid graphene/carbon nanotube films showed a high PCE of 15.36%. Moreover, the devices exhibited excellent stability and could retain 86% of their initial PCE after storage for 500 h in a high-moisture atmosphere (RH 50%). The outstanding stability of PCEs can be attributed to the efficient moisture blocking by the multilayered graphene/carbon nanotube present in the hybrid film. The thin, flexible, and easy-to-synthesize free-standing hybrid graphene/CNT film with high conductivity showed great potential for realizing the low-cost production of highly stable PSCs.

The Research Trends of Pharmacopuncture Therapy on Cervical Pain Caused by Traffic Accidents.

OBJECTIVES: The purpose of this study is to comprehensively review Korean domestic studies and investigate the research trends of pharmacopuncture therapy on cervical pain caused by traffic accidents. METHODS: Domestic studies between February 1999 and May 2020 from four Korean databases were searched with combinations of keywords 'cervical pain', 'traffic accident', 'whiplash injury', and 'pharmacopuncture'. RESULTS: 17 studies were selected for review, including 7 randomized controlled trials, 5 retrospective observational studies, 3 case reports, and 2 non-randomized controlled trials. Each study was reviewed by published year, study type, types of pharmacopuncture solutions, selected acupuncture points, dosage of pharmacopuncture solutions, frequency of treatment, concurrent treatments, outcome measurements, and the effectiveness of pharmacopuncture therapy. The results are as follows (1) It showed that the total number of published studies had increased slightly in the last 10 years compared to the previous decade. (2) The pharmacopuncture solutions used in the studies were in the following order Bee-Venom (), Jungsongouhyul (), Hwangryunhaedoktang () and Soyeom (). Frequently used acupuncture points were GB20, GV21, A-shi point, GV16, EX-B2, and SI15 in order. (3) The most commonly used total injection dosage was 1.0 cc at a time, and the frequency of treatment was twice a week. (4) Concurrent treatments such as acupuncture, herbal medication, physical therapy and Chuna manual therapy were performed in all 17 studies. (5) Pharmacopuncture therapy showed positive effects on cervical pain caused by traffic accidents in all 17 studies reviewed. CONCLUSION: Pharmacopuncture therapy was effective in cervical pain caused by traffic accidents in all 17 studies selected. Further studies will be needed using more larger scales and more objective data to confirm the effectiveness of pharmacopuncture therapy and to generalize its application.

Long-term Survival of a Patient with a Large Hepatocellular Carcinoma with Main Portal Vein Tumor Thrombosis and Spontaneous Tumor Rupture.

Optimal treatments for patients with advanced hepatocellular carcinoma (HCC) are still limited and their prognosis remains dismal. Yet, there have been rare cases that have shed light on longer survival in these patients assisted by various treatments. This paper aims to present an extraordinary case of far advanced HCC that had been properly managed in spite of continuous recurrence. A patient visited the hospital with a ruptured large HCC with main portal vein tumor thrombosis but survived longer than 14 years owing to active and prompt interventions.

Volume change in amygdala enlargement as a prognostic factor in patients with temporal lobe epilepsy: A longitudinal study.

OBJECTIVE: Considering the clinical heterogeneity of temporal lobe epilepsy with amygdala enlargement (TLE-AE), identifying distinct prognostic subgroups of TLE-AE has clinical implications. Until now, baseline volume of the enlarged amygdala (EAV) has consistently failed to predict prognosis in TLE-AE. Based on studies suggesting that patients responsive to antiepileptic drugs (AEDs) exhibit remission of AE on follow-up imaging, we investigated whether reduction rate of EAV is predictive of long-term prognosis in TLE-AE. METHODS: Sixty-one consecutive patients with two separate magnetic resonance imaging (MRI) scans were enrolled. To utilize longitudinally measured biomarkers in prediction, the period beyond the first MRI acquisition was split into two periods: the "observation window" (period between the two MRIs) and "prediction window" (follow-up period beyond the second MRI). Patients were classified according to their AED responsiveness during the observation window, and AED-responsive patients were further subdivided by initial seizure frequency: (a) AED-responsive patients presenting with low-frequency seizures (<5 seizures/3 mo; Group A, n = 25), (b) high-frequency seizures (≥5 seizures/3 mo; Group B, n = 23), and (c) patients with poor initial treatment response (Group C, n = 13). Multivariate logistic regression models were constructed for identification of prognostic factors. Along with factors obtained at baseline, factors derived from the observation window (annual percentage change of EAV [APCEAV] and initial AED responsiveness) were also considered as potential predictors. RESULTS: Favorable initial treatment response and faster volume reduction rate (APCEAV ≤ -5.0%/y) were identified as factors predictive of achieving overall seizure freedom. Among the AED-responsive patients, Group A (low-frequency seizures) showed slower remission of AE and higher rate of seizure recurrence, whereas Group B (high-frequency seizures) exhibited faster remission of AE and lower rate of seizure recurrence. SIGNIFICANCE: Faster recuperation of AE in patients with initial high-frequency seizures may be indicative of seizure-induced changes. As volume reduction rate serves as a prognostic marker in TLE-AE, short-term MRI follow-up may be useful in prognostication.

Body Mass Index and Prognosis in Ischemic Stroke Patients With Type 2 Diabetes Mellitus.

Background: Overweight contributes to type 2 diabetes mellitus (T2DM) development. Although the obesity paradox has been suggested in many vascular diseases, little information is available about stroke patients with T2DM. We investigated whether body mass index (BMI) has a differential impact on the incidence of major adverse cardiovascular events (MACE) in patients with ischemic stroke and T2DM. Methods: This retrospective study used a prospective cohort of patients with acute ischemic stroke and included consecutive patients with T2DM after excluding those with active cancer or who died within 1 month of an index stroke. We investigated the long-term risk of MACE (stroke, myocardial infarction, unstable angina, coronary revascularization procedure, and death) according to BMI. Results: Among the 1,338 patients, MACE occurred in 415 patients (31.1%) during a median follow-up of 3.6 years. Compared to the normal weight group, MACE occurred more frequently in the underweight group [adjusted hazard ratio (HR) 1.55, 95% confidence interval (CI): 1.01-2.38], but less frequently in the overweight group (adjusted HR: 0.87, 95% CI: 0.70-1.08) and obese group (adjusted HR: 0.58, 95% CI: 0.41-0.86) group. In analyses of association between BMI and each component of MACE, stroke and cardiovascular mortality indicated an L- and a U-shaped pattern, respectively. However, fatal or non-fatal stroke showed an inverse pattern, and fatal or non-fatal cardiovascular events showed a reversed J-shaped pattern. Discussions: This study showed the overall presence of the obesity paradox in stroke patients with T2DM. However, obese patients had different risks of cardiovascular events and stroke.

Transparent, Flexible Heater Based on Hybrid 2D Platform of Graphene and Dry-Spun Carbon Nanotubes.

A high-performance, flexible, and transparent heater based on a hybrid of dry-spun carbon nanotubes (CNT), which is pulled out directly from a super vertically aligned CNT forest, and graphene is fabricated. The electrical, optical, and electromechanical properties of two different kinds of hybrid devices, graphene above or below the CNT film, and simple CNT film heating devices that are made of one or two layers of CNTs, are studied. The results prove that the hybrid structured film heaters are superior to the simple CNT film heaters. The simple single-layer CNT film and double-layer CNT film heaters attain maximum temperatures of 48 and 64 °C with transmittances of 73 and 64% at a wavelength of 550 nm, respectively, whereas the single-layer CNT sheet/graphene/PET and graphene/single-layer CNT sheet/PET hybrid heaters attain maximum temperatures of 81 and 85 °C with transmittances of 68 and 71%, respectively. The 10 000 bending cycle test suggests that the graphene/single-layer CNT sheet/PET heater has good mechanical and thermal stability. Further, defrost test and portable heating with a 9 V battery prove the possibility of using the hybrid heater for vehicle defrosting, portable heating, and wearable devices.

Comparison of Adherence to Glimepiride/Metformin Sustained Release Once-daily Versus Glimepiride/Metformin Immediate Release BID Fixed-combination Therapy Using the Medication Event Monitoring System in Patients With Type 2 Diabetes.

PURPOSE: The purpose of this study was to compare the adherence of the glimepiride/metformin sustained release (GM-SR) once-daily fixed-dose combination and glimepiride/metformin immediate release (GM-IR) BID fixed-dose combination in type 2 diabetes therapies. METHODS: An open-label, randomized, multicenter, parallel-group study was conducted at 11 hospitals in the Republic of Korea. A total of 168 patients with type 2 diabetes treated with >4 mg of glimepiride and 1000 mg of metformin by using free or fixed-dose combination therapy for at least 2 weeks were enrolled. Patients were randomized to receive GM-SR 4/1000 mg once-daily or GM-IR 2/500 mg BID for 24 weeks. Adherence was compared by using the Medication Event Monitoring System (MEMS). FINDINGS: A significant difference in adherence was observed between the 2 groups. Overall adherence, defined by the number of container openings divided by the number of prescribed doses, was 91.7% in the GM-SR group and 88.6% in the GM-IR group (P < 0.001). The percentage of treatment days with the correct number of doses taken was 85.3% in the GM-SR group and 75.1% in the GM-IR group (P < 0.001). The percentage of missed doses was 11.7% in the GM-SR group and 15.3% in the GM-IR group (P < 0.001). The percentage of doses taken in the correct time window and therapeutic coverage were higher in the GM-SR group (P < 0.001). There was no significant difference in glycosylated hemoglobin changes or number of adverse events between the 2 groups. A total of 168 patients randomized to receive GM-SR once daily (86 patients) or GM-IR twice daily (82 patients). Mean Age were 57.8 ± 9.6 years old. Male : female ratio was 47.6 : 52.4 %. Body mass index were 66.3 ± 12.0 kg/m2, Diabetes duration were 10.5 ± 6.6 years. IMPLICATIONS: This study showed that patient adherence with GM-SR once daily was significantly better than with GM-IR BID. ClinicalTrials.gov identifier: NCT01620489.

Al-Coated Conductive Fiber Filters for High-Efficiency Electrostatic Filtration: Effects of Electrical and Fiber Structural Properties.

Through the direct decomposition of an Al precursor ink AlH3{O(C4H9)2}, we fabricated an Al-coated conductive fiber filter for the efficient electrostatic removal of airborne particles (>99%) with a low pressure drop (~several Pascals). The effects of the electrical and structural properties of the filters were investigated in terms of collection efficiency, pressure drop, and particle deposition behavior. The collection efficiency did not show a significant correlation with the extent of electrical conductivity, as the filter is electrostatically charged by the metallic Al layers forming electrical networks throughout the fibers. Most of the charged particles were collected via surface filtration by Coulombic interactions; consequently, the filter thickness had little effect on the collection efficiency. Based on simulations of various fiber structures, we found that surface filtration can transition to depth filtration depending on the extent of interfiber distance. Therefore, the effects of structural characteristics on collection efficiency varied depending on the degree of the fiber packing density. This study will offer valuable information pertaining to the development of a conductive metal/polymer composite air filter for an energy-efficient and high-performance electrostatic filtration system.

A Patient with Recurrent Dyskinesia and Hyperpyrexia Syndrome.

Dyskinesia hyperpyrexia syndrome is a rare medical emergency in Parkinson's disease. It is characterized by continuous dyskinesia associated with hyperthermia, rhabdomyolysis, and alteration of the mental state. We present the case of a 74-year-old woman who presented with recurrent dyskinesia hyperpyrexia syndrome. Although some provocation factors and clinical manifestations seem to be shared with parkinsonism hyperpyrexia syndrome, a clear distinction in management should be considered.

Wearable Resistive Pressure Sensor Based on Highly Flexible Carbon Composite Conductors with Irregular Surface Morphology.

Wearable pressure sensors are crucial building blocks for potential applications in real-time health monitoring, artificial electronic skins, and human-to-machine interfaces. Here we present a highly sensitive, simple-architectured wearable resistive pressure sensor based on highly compliant yet robust carbon composite conductors made of a vertically aligned carbon nanotube (VACNT) forest embedded in a polydimethylsiloxane (PDMS) matrix with irregular surface morphology. A roughened surface of the VACNT/PDMS composite conductor is simply formed using a sandblasted silicon master in a low-cost and potentially scalable manner and plays an important role in improving the sensitivity of resistive pressure sensor. After assembling two of the roughened composite conductors, our sensor shows considerable pressure sensitivity of ∼0.3 kPa-1 up to 0.7 kPa as well as stable steady-state responses under various pressures, a wide detectable range of up to 5 kPa before saturation, a relatively fast response time of ∼162 ms, and good reproducibility over 5000 cycles of pressure loading/unloading. The fabricated pressure sensor can be used to detect a wide range of human motions ranging from subtle blood pulses to dynamic joint movements, and it can also be used to map spatial pressure distribution in a multipixel platform (in a 4 × 4 pixel array).

Highly Stretchable, Hysteresis-Free Ionic Liquid-Based Strain Sensor for Precise Human Motion Monitoring.

A highly stretchable, low-cost strain sensor was successfully prepared using an extremely cost-effective ionic liquid of ethylene glycol/sodium chloride. The hysteresis performance of the ionic-liquid-based sensor was able to be improved by introducing a wavy-shaped fluidic channel diminishing the hysteresis by the viscoelastic relaxation of elastomers. From the simulations on visco-hyperelastic behavior of the elastomeric channel, we demonstrated that the wavy structure can offer lower energy dissipation compared to a flat structure under a given deformation. The resistance response of the ionic-liquid-based wavy (ILBW) sensor was fairly deterministic with no hysteresis, and it was well-matched to the theoretically estimated curves. The ILBW sensors exhibited a low degree of hysteresis (0.15% at 250%), low overshoot (1.7% at 150% strain), and outstanding durability (3000 cycles at 300% strain). The ILBW sensor has excellent potential for use in precise and quantitative strain detections in various areas, such as human motion monitoring, healthcare, virtual reality, and smart clothes.

Self-assembled plasmonic nanoparticles on vertically aligned carbon nanotube electrodes via thermal evaporation.

This study details the development of a large-area, three-dimensional (3D), plasmonic integrated electrode (PIE) system. Vertically aligned multiwalled carbon nanotube (VA-MWNT) electrodes are grown and populated with self-assembling silver nanoparticles via thermal evaporation. Due to the geometric and surface characteristics of VA-MWNTs, evaporated silver atoms form nanoparticles approximately 15-20 nm in diameter. The nanoparticles are well distributed on VA-MWNTs, with a 5-10 nm gap between particles. The size and gap of the self-assembled plasmonic nanoparticles is dependent upon both the length of the MWNT and the thickness of the evaporated silver. The wetting properties of water of the VA-MWNT electrodes change from hydrophilic (∼70°) to hydrophobic (∼120°) as a result of the evaporated silver. This effect is particularly pronounced on the VA-MWNT electrodes with a length of 1 µm, where the contact angle is altered from an initial 8° to 124°. Based on UV-visible spectroscopic analysis, plasmonic resonance of the PIE systems occurs at a wavelength of approximately 400 nm. The optical behavior was found to vary as a function of MWNT length, with the exception of MWNT with a length of 1 µm. Using our PIE systems, we were able to obtain clear surface-enhanced Raman scattering (SERS) spectra with a detection limit of ∼10 nM and an enhancement factor of ∼10(6). This PIE system shows promise for use as a novel electrode system in next-generation optoelectronics such as photovoltaics, light-emitting diodes, and solar water splitting.

Elastomer-infiltrated vertically aligned carbon nanotube film-based wavy-configured stretchable conductors.

Elastomer-infiltrated vertically aligned carbon nanotube (VACNT) forests are good candidates for use as stretchable conductors that can retain the electrical properties under relatively large stretching. The electrical performance can be further enhanced in terms of high stretchability and small change in the electrical resistance by using a wavy configuration. In this work, we present a wavy-structured high-performance stretchable conductor prepared by a simple prestraining approach based on polydimethylsiloxane (PDMS)-infiltrated VACNT films. Prior to the infiltration process, the VACNT forests can also be easily micropatterned by a PDMS stamp-assisted contact transfer printing technique. The conductive VACNT forest patterns are fully infiltrated with highly elastic PDMS, and the PDMS/VACNT film is conformally and strongly bonded to the prestrained PDMS substrate with the help of an intermediate thin PDMS layer, resulting in mechanical robustness of the whole device. The fabricated wavy VACNT conductor shows a small resistance change ratio of less than 6% with a tensile strain of up to 100% (prestrained level) and a high reversibility under multiple stretching/releasing cycles with a maximum strain of 100%.

Designed synthesis and stacking architecture of solid and mesoporous TiO(2) nanoparticles for enhancing the light-harvesting efficiency of dye-sensitized solar cells.

We fabricated solid and mesoporous TiO2 nanoparticles (NPs) with relatively large primary sizes of approximately 200 nm via inorganic templates for aero-sol-gel and subsequent aqueous-washing processes. The amount of dye molecules adsorbed by the internal pores in the mesoporous TiO2 NPs was increased by creating the nanopores within the solid TiO2 NPs. Simultaneously, the light-scattering effect of the mesoporous TiO2 NPs fabricated by this approach was secured by maintaining their spherical shape and relatively large average size. By precisely accumulating the fabricated solid or mesoporous 200 nm diameter TiO2 NPs on top of a conventional 25 nm diameter TiO2 NP-based underlayer, we could systematically examine the effect of the solid and mesoporous TiO2 NPs on the photovoltaic performance of dye-sensitized solar cells (DSSCs). Consequently, the stacking architecture of the mesoporous TiO2 NP-based overlayer, which functioned as both a light-scattering and dye-supporting medium, on top of a conventional solid TiO2 NP-based underlayer in a DSSC photoelectrode (i.e., double-layer structures) was found to be very promising for significantly improving the photovoltaic properties of conventional solid TiO2 NP single-layer-based DSSCs.