2,745 research outputs found

    Efficient hybrid solar cells based on solution processed mesoporous TiO2 / Tin (II) sulfide heterojunctions

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    Tin monosulfide (SnS) is emerging as a promising absorber material for the development of low-cost, solution-processable solar cells. Herein, we present a straightforward, solution-based route for the preparation of tin monosulfide (SnS) films employing a green solvent, namely, tetrahydrofuran (THF). We show that the surface coverage and the morphology of the SnS films can be tuned by modification of the precursor solution composition and film deposition conditions. Furthermore, we explore the effect of a PEDOT:PSS interlayer and fabricate solar cells based on the following architecture: FTO/planar-TiO2/mesoporous-TiO2/SnS/P3HT/PEDOT:PSS/Ag. Devices based on this architecture are shown to exhibit power conversion efficiencies (PCEs) of 3.0%, thus demonstrating the potential of our method for the development of low-cost and environmentally friendly solar cells

    The effectiveness of decompression as initial treatment for jaw cysts : a 10-year retrospective study

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    Decompression is an approved alternative to cystectomy in the treatment of jaw cysts. This study aimed to evaluate its effectiveness as an initial procedure, as well as factors with potential to influence outcome. The frequency of decompression was analysed, whether completed in one session or followed by enucleation at the Division of Oral Surgery and Orthodontics, Department of Dental Medicine and Oral Health, Medical University of Graz, from 2005 to 2015. Further analysis focussed on factors potentially influencing outcome: cyst location, histopathology, means of preserving the cyst opening, cyst size, patient age. In all, 53 patients with 55 jaw cysts (mean age of 35.1) were treated by initial decompression in the ten-year period. In the majority of cases, histopathological analysis revealed a follicular cyst (43.6%), followed by odontogenic keratocysts (23.7%), radicular cysts (21.8%), residual cysts (7.3%) and nasopalatine cysts (3.6%) Treatment was completed with a single decompression in 45.5% of the cases. Among those, 72.0% were follicular cysts and 8.0% odontogenic keratocysts. Subsequent enucleation was needed in 54.5% of all cases, with a majority in the keratocystic group (36.7%). Histological findings, means of keeping the cyst open, and patient age were found to influence the effectiveness of decompression. Decompression could be performed as a procedure completed in one session or combined with subsequent enucleation, mainly dependent on histopathological findings. Subsequent enucleation of odontogenic keratocysts is highly recommended

    Improved Charge Separation and Photovoltaic Performance of BiI3 Absorber Layers by Use of an In Situ Formed BiSI Interlayer

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    Stable and nontoxic bismuth iodide (BiI3) is emerging as a promising absorber material for solar cell applications as it possesses favorable optical properties such as a narrow bandgap (1.7 eV) and a high absorption coefficient (105 cm–1) in the visible region. Despite these promising features, solar cells employing this material have only achieved power conversion efficiencies in the region of 1% as of yet, which is distant from the theoretical efficiency limit of 28%. It is reasonable to suppose that the relatively low performance of BiI3-based solar cells may originate from very short carrier lifetimes (180–240 ps) in BiI3, which makes efficient separation of mobile charges a crucial factor for the improvement of the photovoltaic performance of this material. Herein, transient optical spectroscopy is employed to show that the use of a bismuth sulfide iodide interlayer between the electron transport layer (ETL) and the bismuth iodide absorber promotes efficient charge separation. On the basis of this knowledge, we report BiI3 solar cells with a power conversion efficiency of 1.21% using a solar cell architecture comprised of ITO/SnO2/BiSI/BiI3/organic HTM/Au

    Lewis Base Passivation Mediates Charge Transfer at Perovskite Heterojunctions

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    Understanding interfacial charge transfer processes such as trap-mediated recombination and injection into charge transport layers (CTLs) is crucial for the improvement of perovskite solar cells. Herein, we reveal that the chemical binding of charge transport layers to CH3NH3PbI3 defect sites is an integral part of the interfacial charge injection mechanism in both n-i-p and p-i-n architectures. Specifically, we use a mixture of optical and X-ray photoelectron spectroscopy to show that binding interactions occur via Lewis base interactions between electron-donating moieties on hole transport layers and the CH3NH3PbI3 surface. We then correlate the extent of binding with an improvement in the yield and longer lifetime of injected holes with transient absorption spectroscopy. Our results show that passivation-mediated charge transfer has been occurring undetected in some of the most common perovskite configurations and elucidate a key design rule for the chemical structure of next-generation CTLs

    Undifferentiated HepaRG cells show reduced sensitivity to the toxic effects of M8OI through a combination of CYP3A7-mediated oxidation and a reduced reliance on mitochondrial function

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    \ua9 2024 The AuthorsThe methylimidazolium ionic liquid M8OI (1-octyl-3-methylimidazolium chloride, also known as [C8mim]Cl) has been detected in the environment and may represent a hazard trigger for the autoimmune liver disease primary biliary cholangitis, based in part on studies using a rat liver progenitor cell. The effect of M8OI on an equivalent human liver progenitor (undifferentiated HepaRG cells; u-HepaRG) was therefore examined. u-HepaRG cells were less sensitive (>20-fold) to the toxic effects of M8OI. The relative insensitivity of u-HepaRG cells to M8OI was in part, associated with a detoxification by monooxygenation via CYP3A7 followed by further oxidation to a carboxylic acid. Expression of CYP3A7 - in contrast to the related adult hepatic CYP3A4 and CYP3A5 forms - was confirmed in u-HepaRG cells. However, blocking M8OI metabolism with ketoconazole only partly sensitized u-HepaRG cells. Despite similar proliferation rates, u-HepaRG cells consumed around 75% less oxygen than B-13 cells, reflective of reduced dependence on mitochondrial activity (Crabtree effect). Replacing glucose with galactose, resulted in an increase in u-HepaRG cell sensitivity to M8OI, near similar to that seen in B-13 cells. u-HepaRG cells therefore show reduced sensitivity to the toxic effects of M8OI through a combination of metabolic detoxification and their reduced reliance on mitochondrial function

    Hyaluronic acid treatment outcome on the post-extraction wound healing in patients with poorly controlled type 2 diabetes : a randomized controlled split-mouth study

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    Hyaluronic acid is widely used in the medical field. However, there is a lack of research about its effect on patients with certain risks, such as compromised wound healing commonly found in patients with poorly controlled type 2 diabetes. The aim of this study is to investigate the efficacy of hyaluronic acid on the post-extraction wound healing and pain in patients with poorly controlled type 2 diabetes. The randomized controlled split-mouth study was designed, which included 30 patients with poorly controlled type 2 diabetes with a bilaterally same teeth in the lower jaw for extraction. The sockets treated with 0.8% hyaluronic acid represented the study group, while the sockets where hyaluronic acid was not applied represented the control group. Wound closure rate (WCR), clinical scores in wound healing scale (WHS) and pain intensity in Visual analogue scale (VAS) were recorded. Patients were followed up on 5th, 10th, 15th, 20th, 25th day after tooth extraction. The results showed a higher WCR at the extraction site where hyaluronic acid was applied. Also, statistically significant difference was found (p< 0.001). In regards to WHS, the sockets treated with hyaluronic acid showed better healing, especially on day 10 (p=0.006) and day 15 (p=0.021). However, there were no statistically significant differences in VAS scores between groups. Hyaluronic acid placed in post-extraction socket in patients with poorly controlled diabetes may improve wound healing, especially in the first days after application

    Effect of Interfacial Energetics on Charge Transfer from Lead Halide Perovskite to Organic Hole Conductors

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    The control and optimization of interfacial charge transfer processes is crucial to the design of efficient perovskite solar cells. Herein, we measure the yield and kinetics of hole transfer across the methylammonium lead triiodide perovskite|polymeric hole transport material heterojunction, as a function of the interfacial energy offset, ΔE, between the highest occupied molecular orbital of the hole transport material and the valence band edge of the perovskite. A combination of steady-state and time-resolved photoluminescence, along with transient absorption spectroscopy, revealed that only a small driving energy (ΔE ∼ 0.07 eV) is required to induce highly efficient hole transfer. The findings of this paper suggest that further improvements in the open-circuit voltage, and so the power conversion efficiency, of perovskite solar cells could be achieved by incorporating hole transport materials that provide an interfacial energy offset in the range 0 < ΔE < 0.18 eV

    Evaluating QBF Solvers: Quantifier Alternations Matter

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    We present an experimental study of the effects of quantifier alternations on the evaluation of quantified Boolean formula (QBF) solvers. The number of quantifier alternations in a QBF in prenex conjunctive normal form (PCNF) is directly related to the theoretical hardness of the respective QBF satisfiability problem in the polynomial hierarchy. We show empirically that the performance of solvers based on different solving paradigms substantially varies depending on the numbers of alternations in PCNFs. In related theoretical work, quantifier alternations have become the focus of understanding the strengths and weaknesses of various QBF proof systems implemented in solvers. Our results motivate the development of methods to evaluate orthogonal solving paradigms by taking quantifier alternations into account. This is necessary to showcase the broad range of existing QBF solving paradigms for practical QBF applications. Moreover, we highlight the potential of combining different approaches and QBF proof systems in solvers.Comment: preprint of a paper to be published at CP 2018, LNCS, Springer, including appendi

    Benefits of Whole-Body Vibration, as a component of the pulmonary rehabilitation, in patients with Chronic Obstructive Pulmonary Disease: A narrative review with a suitable approach

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    Appropriate management, including pulmonary rehabilitation, associated with correct diagnosis of chronic obstructive pulmonary disease (COPD) in patients can contribute to improving clinical conditions of these patients. Physical activity is recommended for COPD patients. Whole-body vibration (WBV) is a modality of physical activity. Putting together the biological effects and safe use of WBV, it may be a potentially feasible intervention to add to pulmonary rehabilitation. The purpose of this investigation was to systematically review studies regarding the effects of WBV, as a component of the pulmonary rehabilitation, in patients with COPD

    Effects of Male Hypogonadism on Regional Adipose Tissue Fatty Acid Storage and Lipogenic Proteins

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    Testosterone has long been known to affect body fat distribution, although the underlying mechanisms remain elusive. We investigated the effects of chronic hypogonadism in men on adipose tissue fatty acid (FA) storage and FA storage factors. Twelve men with chronic hypogonadism and 13 control men matched for age and body composition: 1) underwent measures of body composition with dual energy x-ray absorptiometry and an abdominal CT scan; 2) consumed an experimental meal containing [3H]triolein to determine the fate of meal FA (biopsy-measured adipose storage vs. oxidation); 3) received infusions of [U-13C]palmitate and [1-14C]palmitate to measure rates of direct free (F)FA storage (adipose biopsies). Adipose tissue lipoprotein lipase, acyl-CoA synthetase (ACS), and diacylglycerol acetyl-transferase (DGAT) activities, as well as, CD36 content were measured to understand the mechanism by which alterations in fat storage occur in response to testosterone deficiency. Results of the study showed that hypogonadal men stored a greater proportion of both dietary FA and FFA in lower body subcutaneous fat than did eugonadal men (both p<0.05). Femoral adipose tissue ACS activity was significantly greater in hypogonadal than eugonadal men, whereas CD36 and DGAT were not different between the two groups. The relationships between these proteins and FA storage varied somewhat between the two groups. We conclude that chronic effects of testosterone deficiency has effects on leg adipose tissue ACS activity which may relate to greater lower body FA storage. These results provide further insight into the role of androgens in body fat distribution and adipose tissue metabolism in humans
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