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The main causes of the large open-circuit voltage (Voc)-deficit in kesterite-based thin-film solar cells (TFSCs) are the high concentration of defects, related defect clusters, and poor band tailing characteristics. We report thorough investigations of defects, defect clusters, and band tailing characteristics in Cu2ZnSn(S,Se)4 (CZTSSe) thin films as well as their impact on device performance. Through detailed analyses, we find that (i) the relative concentration of the ZnCu and SnCu defects and B-type [2ZnCu + ZnSn] and C-type [2CuZn + SnZn] defect clusters plays a critical role in determining the kesterite device parameters such as the Voc, fill factor, and power conversion efficiency (PCE) under Cu-poor and Zn-rich conditions; in particular, we observed that the higher Zn content has minimal impact on VCu formation; though, ZnCu shallow donors over the optimal concentration cause the electron sink/electron localization to facilitate carrier recombination and induce Voc loss in the device. (ii) the trend in short circuit current densities (Jsc) is independent of defects and defect cluster concentrations; (iii) band tailing characteristics calculated from the energy difference between bandgap energy (Eg) from external quantum efficiency (EQE) and photoluminescence (PL) spectra can also be affected by the existence of minor secondary phases on the kesterite surface. This work offers new insights and correlations between defects, defect clusters, band tailing characteristics, and device performance, which will help further improve the performance of kesterite-based TFSCs. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the embolic effect of fish-derived gelatin microparticles (GMPs) and compare the degradation periods and biocompatibilities of different molecular weight (MW) GMPs in a rabbit model.Methods: GMPs were designed to degrade within 21 days (high MW GMP, 15-30 kDa) and 2 days (low MW GMP, 5-15 kDa) in vivo. Renal arteries of 24 rabbits were embolized using both high and low MW GMPs (155-350 µm). Rabbits were sacrificed either immediately after embolization, or after follow-up (F/U) angiogram on days 2 and 21 of embolization, respectively (4 rabbits in each of the 6 subgroups). Pathological changes of recanalized vessels were evaluated using the Banff classification. For the in vitro study, each type of GMP was mixed with normal saline and morphological changes were compared for 14 days.Results: Fish-derived GMPs showed effective embolization. On 2-day F/U angiography, occluded vessels were more recanalized to the peripheral branches in low MW group. On day 21, a parenchymal perfusion defect recovered to a greater extent in low MW group than that in high MW group. Mean Banff scores for intimal arteritis on 2-day F/U and interstitial fibrosis on 21-day F/U were higher in high MW group (1.75 ± 0.58 vs. 0.19 ± 0.4 and 2.56 ± 0.63 vs. 0.88 ± 0.89; P < .001). On in vitro assessment, low MW GMP lost the spherical shape and degraded, and was invisible on microscopy on day 6, whereas high MW GMP was only partially degraded after 2 weeks.Conclusion: Fish-derived GMPs showed effective embolization in a rabbit model. Low MW GMPs degraded within 2 days with a low inflammatory response. [ABSTRACT FROM AUTHOR]

Purpose The purpose of this study was to investigate whether routine insertion of peripherally inserted central catheter (PICC) at admission to a hospice-palliative care (HPC) unit is acceptable in terms of safety and efficacy and whether it results in superior patient satisfaction compared to usual intravenous (IV) access. Materials and Methods Terminally ill cancer patients were randomly assigned to two arms: routine PICC access and usual IV access arm. The primary endpoint was IV maintenance success rate, defined as the rate of functional IV maintenance until the intended time (discharge, transfer, or death). Results A total of 66 terminally ill cancer patients were enrolled and randomized to study arms. Among them, 57 patients (routine PICC, 29; usual IV, 28) were analyzed. In the routine PICC arm, mean time to PICC was 0.84 days (range, 0 to 3 days), 27 patients maintained PICC with function until the intended time. In the usual IV arm, 11 patients maintained peripheral IV access until the intended time, and 15 patients underwent PICC insertion. The IV maintenance success rate in the routine PICC arm (27/29, 93.1%) was similar to that in the usual IV arm (26/28, 92.8%, p=0.958). Patient satisfaction at day 5 was better in the routine PICC arm (97%, 'a little comfort' or 'much comfort') compared with the usual IV arm (21%) (p < 0.001). Conclusion Routine PICC insertion in terminally ill cancer patients was comparable in safety and efficacy and resulted in superior satisfaction compared with usual IV access. Thus, routine PICC insertion could be considered at admission to the HPC unit. [ABSTRACT FROM AUTHOR]

Hepatic duct diverticulum is a rare form of choledochal cyst that does not fit into the most widely used Todani classification system. Because of its rarity, it may be difficult for clinicians to diagnose and treat it. Here, we present a case of left hepatic diverticulum in a 57-year-old woman with epigastric pain. At presentation, there were mild elevations in the liver function tests. Computed tomography and magnetic resonance cholangiopancreatography showed diverticulum-like cystic lesion with sludge ball near the confluence portion of both intrahepatic bile duct, but the origin of the lesion could not be identified. The clinical impression was type II choledochal cyst. Surgical excision was planned due to recurrent abdominal pain. The operative findings revealed diverticulum arising from left hepatic duct. Histopathology confirmed the lesion to be diverticulum lined by biliary epithelium. The patient had no postoperative complication and no further symptoms since the operation. [ABSTRACT FROM AUTHOR]

A low-cost, highly efficient and durable photoelectrochemical (PEC) water-splitting system can be realized through designing a hierarchical core/shell nanostructured photoanode entirely composed of Earth-abundant elements. Herein, we report the rational design of a core/shell nanostructured photoanode with a TiO2 nanorod (NR) array as the core and a highly active Earth-abundant NiFe oxyhydroxide ((Ni1-xFex)OOH, NiFeOOH) oxygen evolution catalyst (OEC) as the shell for PEC water oxidation. Specifically, the NiFeOOH nanosheets were prepared via a facile, one-step electroless deposition method for a short reaction time of 10 min at room temperature. The TiO2/NiFeOOH core/shell nanostructured photoanode exhibits an unprecedented enhancement in photocurrent density (3.85 mA cm-2 at 1.23 V vs. a reversible hydrogen electrode, (RHE)), no decay in photocurrent density over 24 h, and an obvious cathodic onset potential shift of 133 mV compared to the TiO2 NRs (0.73 mA cm-2 at 1.23 V vs. RHE). The electron transfer mechanism is discussed through electrochemical impedance spectroscopy studies and calculated band alignments via ultraviolet photoelectron spectroscopy characterization. This work not only suggests a simple, room temperature electroless strategy for integrating Earth-abundant catalysts with photoanodes, but also accelerates the development of rationally designed core/shell photoanodes for efficient and durable solar water oxidation. [ABSTRACT FROM AUTHOR]

We report the growth of Ba1–xLaxSnO3 (x=0.00, 0.005, 0.01, 0.02, and 0.04) thin films on the insulating BaSnO3(001) substrate by pulsed laser deposition. The insulating BaSnO3 substrates were grown by the Cu2O-CuO flux, in which the molar fraction of KClO4 was systematically increased to reduce electron carriers and thus induce a doping induced metal-insulator transition, exhibiting a resistivity increase from ~10–3 to ~1012Ωcm at room temperature. We find that all the Ba1–xLaxSnO3 films are epitaxial, showing good in-plane lattice matching with the substrate as confirmed by X-ray reciprocal space mappings and transmission electron microscopy studies. The Ba1–xLaxSnO3 (x=0.005–0.04) films showed degenerate semiconducting behavior, and the electron mobility at room temperature reached 100 and 85 cm2V–1 s–1 at doping levels 1.3×1020 and 6.8×1019 cm–3, respectively. This work demonstrates that thin perovskite stannate films of high quality can be grown on the BaSnO3(001) substrates for potential applications in transparent electronic devices. [ABSTRACT FROM AUTHOR]

In this study, we design, fabricate and evaluate a resonant micromirror that can amplify the vibration amplitude by mechanical parametric amplification. It is shown that the spring constant of torsion bars supporting the micromirror can be varied by stress generated using an electrothermal actuator, which can tune the resonant frequency of the torsional mode. The parametric amplification of the vibration of the torsional mode is demonstrated by applying a pumping signal using the electrothermal actuator in addition to a driving signal. As the driving power increases, the resonant frequency increases owing to the nonlinear spring effect of the torsional spring. However, the frequency shift can be compensated for by applying stress to the torsional spring using the frequency tuning mechanism for the reliable operation of the micromirror. [ABSTRACT FROM AUTHOR]

With the earth's abundance of kesterite, recent progress in chalcogenide based Cu2ZnSn(Sx,Se1-x)4 (CZTSSe) thin films has drawn prime attention in thin film solar cells (TFSCs) research and development. This review is focused on the current developments in the synthesis of CZTS nanocrystals (NCs) using a hot injection (HI) technique and provides comprehensive discussions on the current status of CZTSSe TFSCs. This article begins with a description of the advantages of nanoparticulate based thin films, and then introduces the basics of this technique and the corresponding growth mechanism is also discussed. A brief overview further addresses a series of investigations on the developments in the HI based CZTSSe NCs using different solvents in terms of their high toxicity to environmentally benign materials. A variety of recipes and techniques for the NCs ink formulation and thereby the preparation of absorber layers using NC inks are outlined, respectively. The deposition of precursor thin films, post-deposition processes such as sulfurization or selenization treatments and the fabrication of CZTSSe NCs based solar cells and their performances are discussed. Finally, we discussed concluding remarks and the perspectives for further developments in the existing research on CZTSSe based nanoparticulate (NP) TFSCs towards future green technology. [ABSTRACT FROM AUTHOR]

Tailoring the nano-morphology and nano-architecture of titanium dioxide (TiO2 ) is the most important task in the third generation solar cells (Dye sensitized solar cells/Quantum dot sensitized solar cells) (DSSCs/ QDSSCs). In this article we present complete study of surfactant free synthesis of TiO2 nanostructures by a simple and promising hydrothermal route. The plethora of nanostructures like nanoparticles clusters, 1D tetragonal nanorods, 3D dendrites containing nanorods having ,30 nm diameter and 3D hollow urchin like have been synthesized. These nanostructures possess effective large surface area and thus useful in DSSCs. In the present work, 7.16% power conversion efficiency has been demonstrated for 3D dendritic hollow urchin like morphology. Our synthetic strategy provides an effective solution for surfactant free synthesis of efficient TiO2 nanoarchitectures. [ABSTRACT FROM AUTHOR]

Tailoring the nano-morphology and nano-architecture of titanium dioxide (TiO2) is the most important task in the third generation solar cells (Dye sensitized solar cells/Quantum dot sensitized solar cells) (DSSCs/ QDSSCs). In this article we present complete study of surfactant free synthesis of TiO2 nanostructures by a simple and promising hydrothermal route. The plethora of nanostructures like nanoparticles clusters, 1D tetragonal nanorods, 3D dendrites containing nanorods having ,30 nm diameter and 3D hollow urchin like have been synthesized. These nanostructures possess effective large surface area and thus useful in DSSCs. In the present work, 7.16% power conversion efficiency has been demonstrated for 3D dendritic hollow urchin like morphology. Our synthetic strategy provides an effective solution for surfactant free synthesis of efficient TiO2 nanoarchitectures. [ABSTRACT FROM AUTHOR]

Cu2ZnSnS4 (CZTS) thin films were prepared by the sequential sulfurization of a co-sputtered precursor with a multitarget (Cu, ZnS, and SnS2) sputtering system. In order to investigate the crystallization behaviour of the thin films, the precursors were sulfurized in a tube furnace at different temperatures for different time durations. The Raman spectra of the sulfurized thin films showed that their crystallinity gradually improved with an increase in the sulfurization temperature and duration. However, transmission electron microscopy revealed an unexpected result--the precursor thin films were not completely transformed to the CZTS phase and showed the presence of uncrystallized material when sulfurized at 250-400 °C for 60 min and at 500 °C for 30 min. Thus, the crystallization of the co-sputtered precursor thin films showed a strong dependence on the sulfurization temperature and duration. The crystallization mechanism of the precursor thin films was understood on the basis of these results and has been described in this paper. The understanding of this mechanism may improve the standard preparation method for high-quality CZTS absorber layers. [ABSTRACT FROM AUTHOR]

A blue tattoo is more resistant to laser therapy than black or brown tattoos. This study aimed to confirm titanium as a key response-disturbing constituent in a blue tattoo ink after Nd-YAG (1064 nm) laser treatment by animal experiments. Rabbits' backs were tattooed with four ink colours, and the Nd-YAG (1064 nm) laser was used to remove the tattoos. The response to the laser treatment in the rabbits was evaluated and electron microscopic studies were also performed. Excellent to fair responses were observed for the black, brown and dark brown inks, but the blue ink responded poorly to the laser. Histological examination indicated that the blue pigments were unchanged even after the laser treatment. Quantitative energy dispersive spectrometry revealed that blue ink contained high amounts of titanium. Our animal experiments confirm that a blue tattoo ink containing titanium, is a key element in poor response to the Nd-YAG laser. [ABSTRACT FROM AUTHOR]

Conversion of electromagnetic energy into heat by nanoparticles (NPs) has the potential to be a powerful, non-invasive technique for biomedical applications such as magnetic fluid hyperthermia, drug release, disease treatment and remote control of single cell functions, but poor conversion efficiencies have hindered practical applications so far. In this paper, an attempt has been made to increase the efficiency of magnetic thermal induction by NPs. To increase the efficiency of magnetic thermal induction by NPs, one can take advantage of the exchange coupling between a magnetically hard core and magnetically soft shell to tune the magnetic properties of the NP and maximize the specific absorption rate, which is the gauge of conversion efficiency. In order to examine the tunability of magnetocrystalline anisotropy and its magnetic heating power, a representative magnetically hard material (CoFe2O4) has been coupled to a soft material (Ni0.5Zn0.5Fe2O4). The synthesized NPs show specific absorption rates that are of an order of magnitude larger than the conventional one. [ABSTRACT FROM AUTHOR]

Thin films of Ga-doped ZnO (GZO) were prepared on glass and Al2O3 (0001) substrates by using RF magnetron sputtering at a substrate temperature of 350 °C, RF power of 175 W, and working pressure of 6 mTorr. The effect of film thickness and substrate type on the structural and electrical properties of the thin films was investigated. X-ray diffraction study showed that GZO thin films on glass substrates were grown as a polycrystalline hexagonal wurtzite phase with a c-axis preferred, out-of-plane orientation and random in-plane orientation. However, GZO thin films on Al2O3 (0001) substrates were epitaxially grown with an orientation relationship of . The structural images from scanning electron microscopy and atomic force microscopy showed that the GZO thin films on glass substrates had a rougher surface morphology than those on Al2O3 (0001) substrates. The electrical resistivity of 1000 nm-thick GZO thin films grown on glass and Al2O3 (0001) substrates was 3.04 x 10-4 Ocm and 1.50 x 10-4 Ocm, respectively. It was also found that the electrical resistivity difference between the films on the two substrates decreased from 9.48 x 10-4 Ocm to 1.45 x 10-4 Ocm with increasing the film thickness from 100 nm to 1000 nm. [ABSTRACT FROM AUTHOR]

The aim of the present work was to study the morphological, structural, and chemical analysis as a function of depth in vanadium alloys with a 5 at.% of titanium implanted at 673 K with 1.2 keV N+ ions, by transmission electron microscopy (TEM), glow discharge (GD) analysis, and x-ray photoemission spectroscopy. These results are correlated with those of previously published nanoindentation tests, and the species and chemical states responsible for the increase in hardness are identified. The maximum increase in hardness corresponds to the highest N concentration, measured by both photoemission spectroscopy and GD. In addition, the thickness of the layer (∼1000 nm), where structural modifications are observed using TEM, can also be directly correlated with the thickness of the implanted layer, where an incremental increase in hardness has previously been measured. These findings support the conclusion that the formation of vanadium and titanium nitride/oxynitrides (-N-O,-O-N-H) compounds are responsible for the increased hardness of these V-5at.% Ti samples implanted with N at low ion energy and high sample temperature. [ABSTRACT FROM AUTHOR]

Epitaxial ZnO thin films were grown on (111) MgAl2O4 with a pre-seeded, two-step chemical solution deposition process. Isolated, epitaxial ZnO islands (seeds) were formed on the substrate in the first step by spin coating a very thin layer of the precursor solution and heat-treating to 950 °C/3 h. In the second step, the seeded substrate was coated with another layer of precursor to produce an epitaxial film. The result was compared with the case in which a MgAl2O4 substrate was not seeded. Both the seeded and unseeded ZnO films have out-of-plane and in-plane orientation relationships of (0001)ZnO ? (111)MgAl2O4 and [11-20]ZnO ? [-1-12]MgAl2O4, respectively. However, only the seeded ZnO films have very faceted surface morphology without grain boundaries, indicating epitaxy, whereas the unseeded ZnO films have deep grain boundaries indicative of polycrystalline nature. This result shows that the formation of seeds in the first step plays an instrumental role in the formation of an epitaxial ZnO film. [ABSTRACT FROM AUTHOR]