Purpose
To compare the Celect and Denali filters in terms of complex filter retrieval and indwelling complications after a 2-month indwelling time.
Materials and Methods
In this prospective, ...randomized trial, 153 subjects were assessed for eligibility between May 2016 and July 2018. A total of 136 participants were randomly assigned to receive either Celect (
n
= 68) or Denali (
n
= 68) filter placement in the infrarenal inferior vena cava. Tilt angles at placement and retrieval and rates of overall filter retrieval, indwelling complication, and complex retrieval were compared.
Results
Of 136 participants (mean age, 62 ± 12.8 years, 55 male), 24 (17.6%) were lost to follow-up. The mean indwelling time of filter was 60.4 ± 7 days and there was no significant difference in the baseline characteristics between the two groups. Filter retrieval was successful in all participants (112/112, 100%). Significantly higher rates of filter tilt > 15° (
n
= 8) and strut penetration (
n
= 14) were found with the Celect filter than with the Denali filter (1 significant tilt and 1 penetration) (
P
= 0.033 and 0.001, respectively). No filter fractures were observed and there was no significant difference in tip embedment, filter fracture, filter migration, or mean fluoroscopy times. There were 3 cases of complex retrieval (1 for Denali vs. 2 for Celect,
P
= 0.500), for which the loop-snare technique was used.
Conclusion
Denali filters demonstrated significantly lower rates of tilt angle > 15° and strut penetration. However, there was no significant difference in the complex filter retrieval rate between the Celect and Denali filters.
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•We present the NO2 gas sensing properties of SnO2-ZrO2 core-shell nanowires.•The gas sensors showed an optimal sensing temperature at a relatively low temperature (≤ 150 °C).•The ...dependence of responses to shell thickness was explained.
We present novel research devoted to the synthesis of SnO2-ZrO2 core-shell nanowires (C-S NWs) and investigation of their NO2 gas sensing properties. ZrO2 shell layer was deposited on networked SnO2 NWs. The ZrO2 shell thickness was varied using four different numbers of atomic layer deposition (ALD) cycles (50, 100, 150 and 200). Structural, morphological and chemical composition of the synthesized products were confirmed by different characterization techniques. The gas sensors showed an optimal sensing temperature at a relatively low temperature (≤ 150 °C). NO2 sensing results showed a strong dependence of response on the thickness of the ZrO2 shell, or equivalently the number of ALD cycles of ZrO2. The optimal sensor with a ZrO2 shell deposited at 150 ALD cycles (24.1 nm thick) exhibited a high response of (Rg/Ra) 24.7–10 ppm NO2 gas and revealed a good selectivity to NO2 gas. Also, with an increase in the thickness of the ZrO2 shell, the negative influence of humidity on the sensor response to NO2 was significantly decreased. The sensing mechanism involves NO2 removing electrons from the ZrO2 shell. The dependence of responses to shell thickness was explained based on two different regimes, i.e., the surface-electron-limiting regime and adsorbing species-limiting regime. The results obtained in this study can be used for further exploration of the sensing properties of ZrO2 as a novel shell material.
We report the effect of zirconium oxide (ZrO2) layers on the electrical characteristics of multilayered tin disulfide (SnS2) formed by atomic layer deposition (ALD) at low temperatures. SnS2 is a ...two-dimensional (2D) layered material which exhibits a promising electrical characteristics as a channel material for field-effect transistors (FETs) because of its high mobility, good on/off ratio and low temperature processability. In order to apply these 2D materials to large-scale and flexible electronics, it is essential to develop processes that are compatible with current electronic device manufacturing technology which should be conducted at low temperatures. Here, we deposited a crystalline SnS2 at 150 °C using ALD, and we then annealed at 300 °C. X-ray diffraction (XRD) and Raman spectroscopy measurements before and after the annealing showed that SnS2 had a hexagonal (001) peak at 14.9° and A1g mode at 313 cm−1. The annealed SnS2 exhibited clearly a layered structure confirmed by the high resolution transmission electron microscope (HRTEM) images. Back-gate FETs with SnS2 channel sandwiched by top and bottom ZrO2 on p++Si/SiO2 substrate were suggested to improve electrical characteristics. We used a bottom ZrO2 layer to increase adhesion between the channel and the substrate and a top ZrO2 layer to improve contact property, passivate surface, and protect from process-induced damages to the channel. ZTZ (ZrO2/SnS2/ZrO2) FETs showed improved electrical characteristics with an on/off ratio of from 0.39×103 to 6.39×103 and a mobility of from 0.0076 cm2/Vs to 0.06 cm2/Vs.
Combination of photodynamic therapy (PDT) with photothermal therapy (PTT) has achieved significantly improved therapeutic efficacy compared to a single phototherapy modality. However, most ...nanomaterials used for combined PDT/PTT are made of non-biodegradable materials (e.g., gold nanorods, carbon nanotubes, and graphenes) and may remain intact in the body for long time, raising concerns over their potential long-term toxicity. Here we report a new combined PDT/PTT nanomedicine, designated SP
NPs, that exhibit photo-decomposable, photodynamic and photothermal properties. SP
NPs were prepared by self-assembly of PEGylated cypate, comprising FDA-approved PEG and an ICG derivative. We confirmed the ability of SP
NPs to generate both singlet oxygen for a photodynamic effect and heat for photothermal therapy in response to NIR laser irradiation in vitro. Also, the unique ability of SP
NPs to undergo irreversible decomposition upon NIR laser irradiation was demonstrated. Further our experimental results demonstrated that SP
NPs strongly accumulated in tumor tissue owing to their highly PEGylated surface and relatively small size (~60 nm), offering subsequent imaging-guided combined PDT/PTT treatment that resulted in tumor eradication and prolonged survival of mice. Taken together, our SP
NPs described here may represent a novel and facile approach for next-generation theranostics with great promise for translation into clinical practice in the future.
In this report, two types of substrates were prepared for deposition of few-layer tin disulfide (SnS2) via atomic layer deposition (ALD). The first substrate was prepared using a conventional ...cleaning method, while the second substrate was rinsed with buffered oxide etcher (BOE) solution after conventional cleaning. Changes in the substrate were confirmed by X-ray photoelectron spectroscopy, contact angle measurements, and electron spin resonance. Characteristics of the SnS2 thin films were determined by X-ray diffraction, Raman analysis, Fourier transform-infrared spectroscopy, atomic force microscopy, and X-ray photoelectron spectroscopy. To investigate growth rate, thickness was measured as a function of ALD cycle number by atomic force microscopy, and 2D layered structure was confirmed by transmission electron microscopy. Findings confirmed that surface treatment using BOE solution was related to an increased growth rate during the initial ALD process. Finally, back-gate field effect transistors based on ALD-grown SnS2 film prepared on substrate that received diluted-BOE surface treatment showed marginal improvement in current on/off ratio from 2.9 × 105 to 6.5 × 105 and mobility from 0.22 cm2/Vs to 0.31 cm2/Vs compared to ALD-grown SnS2 film prepared on bare substrate.
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•SnS2 thin films were grown by atomic layer deposition.•Bare and surface treated substrates were used to deposit SnS2.•Buffered oxide etchant solution was used to surface treatment.•Hydrophilicity of two different substrates was investigated.•Growth rate and transport properties of SnS2 thin films were investigated.
We used atomic layer deposition (ALD) to evaluate the effect of single Al2O3 cycle insertion at various locations on SnO2 and Al-doped SnO2 thin film transistors (TFTs). The ALD process was used to ...deposit the SnO2 thin film in 67 cycles (5 nm thickness). The position of the Al doped layer of Al-doped SnO2 was controlled by inserting a single Al2O3 cycle into the 56th, 34th and 12th cycles out of 67 cycles. The inserted Al doping layer was analyzed by secondary ion mass spectrometry (SIMS). Crystallinity and thickness of SnO2 and Al-doped SnO2 were measured using transmission electron microscope (TEM). Al-doped SnO2 thin films were prepared at different single Al2O3 cyclic positions for use as channel layers. XPS analysis showed that the oxygen vacancies within the film ranged from 32.8% to 41.6%. Also, the carrier concentration varied from 1.44 x 1016 to 2.80 x 1020 cm−3 depending on the Al doping position based on Hall measurements. In addition, the field effect mobility and on/off current ratios ranged from 1.4 to 8.1 cm2/Vsec and from 5.29 x 102 to 1.56 x 107, respectively. Lastly, the threshold voltage varied from −6.56 to 11.60 V. Overall, SnO2 and Al doped SnO2 channel layers deposited using atomic layer deposition were adjusted to exhibit switching characteristics by inserting a single Al2O3 cycle based on position.
Silicon nitride (SiNx) thin films using 1,3-di-isopropylamino-2,4-dimethylcyclosilazane (CSN-2) and N2 plasma were investigated. The growth rate of SiNx thin films was saturated in the range of ...200–500 °C, yielding approximately 0.38 Å/cycle, and featuring a wide process window. The physical and chemical properties of the SiNx films were investigated as a function of deposition temperature. As temperature was increased, transmission electron microscopy (TEM) analysis confirmed that a conformal thin film was obtained. Also, we developed a three-step process in which the H2 plasma step was introduced before the N2 plasma step. In order to investigate the effect of H2 plasma, we evaluated the growth rate, step coverage, and wet etch rate according to H2 plasma exposure time (10–30 s). As a result, the side step coverage increased from 82% to 105% and the bottom step coverages increased from 90% to 110% in the narrow pattern. By increasing the H2 plasma to 30 s, the wet etch rate was 32 Å/min, which is much lower than the case of only N2 plasma (43 Å/min).
VO2 is an attractive candidate as a transition metal oxide switching material as a selection device for reduction of sneak-path current. We demonstrate deposition of nanoscale VO2 thin films via ...thermal atomic layer deposition (ALD) with H2O reactant. Using this method, we demonstrate VO2 thin films with high-quality characteristics, including crystallinity, reproducibility using X-ray diffraction, and X-ray photoelectron spectroscopy measurement. We also present a method that can increase uniformity and thin film quality by splitting the pulse cycle into two using scanning electron microscope measurement. We demonstrate an ON / OFF ratio of about 40, which is caused by metal insulator transition (MIT) of VO2 thin film. ALDdeposited VO2 films with high film uniformity can be applied to next-generation nonvolatile memory devices with high density due to their metal-insulator transition characteristic with high current density, fast switching speed, and high ON / OFF ratio. KCI Citation Count: 0
Photocrosslinked DNA Nanospheres for Drug Delivery Roh, Young Hoon; Lee, Jong Bum; Tan, Shawn J. ...
Macromolecular rapid communications,
July 1, 2010, Letnik:
31, Številka:
13
Journal Article, Conference Proceeding
Recenzirano
DNA has been employed as both a genetic and a generic material. X‐shaped DNA (X‐DNA) in particular has four branched arms, providing multivalent functionalities that can allow for simultaneous ...multiple crosslinking. Here we report the synthesis of four acrylate‐functionalized X‐DNA monomers that can be further photocrosslinked to form monodisperse and tunable DNA nanospheres. In particular, the size and surface charge of these nanospheres were precisely controlled in a linear fashion, simply by tuning the monomer concentration in the reaction. The morphology and surface properties of the nanospheres were characterized using FT‐IR, HPLC, TEM, AFM, zeta potential, and DLS analysis. In vitro studies in mammalian cells revealed that these DNA nanospheres demonstrated significant efficacy in the delivery of doxorubicin. These results highlight the potential of using DNA as material building blocks to design novel nanocarriers with properties tailored for the delivery of drugs in general and DNA/RNA in particular.
Novel monodisperse and tunable DNA nanospheres have been generated via rapid photocrosslinking of photoreactive branched DNA monomers. This paper describes the synthesis and characterization of photocrosslinked DNA nanospheres that may have potential applications as drug delivery carriers.
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