Search

The application of iron oxide quantum dots (IOQDs) in this study led to the development of a straightforward, easy, and selective approach for cytosine sensing. To examine the capability of IOQDs in detecting nucleobases, attempts have been made to gain insight into the characteristics of IOQDs, including UV/Vis spectroscopic analysis, infrared spectroscopy, fluorescence spectroscopy, transmission electron microscopy, and powder‐XRD. We introduced IOQDs with a mean particle size distribution of 5.71 ± 0.08 nm for detecting cytosine by harnessing a turn‐on fluorescence phenomenon. The fostering fluorescence response of IOQDs was triggered in the presence of cytosine. In comparison, the presence of other nucleobases did not further induce the fluorescence signal of IOQDs. It was concluded that the hydrogen bonding bridging the carboxylate and hydroxyl groups on the surface of QDs with the amine groups of cytosine results in the elevation of IOQDs fluorescence. [ABSTRACT FROM AUTHOR]

In this study, a series of Al complexes bearing amidates, thioamidates, ureidates, and thioureidates were synthesized and their catalytic activity for ε-caprolactone (CL) polymerization was evaluated. SPr-Al exhibited a higher catalytic activity than OPr-Al (3.2 times as high for CL polymerization; [CL] : [SPr-Al] : [BnOH] = 100 : 0.5 : 2; [SPr-Al] = 10 mM, conv. = 93% after 14 min at 25 °C), and USCl-Al exhibited a higher catalytic activity than UCl-Al (4.6 times as high for CL polymerization; [CL] : [USCl-Al] : [BnOH] = 100 : 0.5 : 2; [USCl-Al] = 10 mM, conv. = 90% after 15 min at 25 °C). Regardless of whether aluminum amidates or ureidates were present, thioligands improved the polymerization rate of aluminum catalysts. Density functional theory calculations revealed that the eight-membered ring [SPr-AlOMe2]2 decomposed into the four-membered ring SPr-AlOMe2. However, [OPr-AlOMe2]2 did not decompose because of its strong bridging Al–O bond. The overall activation energy required for CL polymerization was lower when using [SPr-AlOMe2]2 (18.1 kcal mol−1) as a catalyst than when using [OPr-AlOMe2]2 (23.9 kcal mol−1). This is because the TS2a transition state of SPr-AlOMe2 had a more open coordination geometry with a small N–Al–S angle (72.91°) than did TS3c of [OPr-AlOMe2]2, the crowded highest-energy transition state of [OPr-AlOMe2]2 with a larger N–Al–O angle (99.63°). [ABSTRACT FROM AUTHOR]

Polyphyllin G, a pennogenyl saponin extracted from Paris polyphylla, has been shown to possess antitumor effects. In this study, we demonstrated that doxycycline, an antibiotic medicine, could significantly enhance the sensitivities of osteosarcoma cell lines to polyphyllin G. As the cells were pretreated with doxycycline at non‐toxic concentrations and then co‐exposed to polyphyllin G, this combination could induce a rapid cell death distinct from apoptosis. The non‐apoptotic cell death was characterized by a loss of integrity of plasma membrane without externalization of phosphatidyl serine. Furthermore, this combined treatment resulted in suppression of cell viability and colony‐forming ability, and increased the level of γ‐H2A.X, a critical marker for DNA damage, in osteosarcoma cell lines. When examining the underlying mechanism, it was revealed combination of polyphyllin G and doxycycline triggered an enhanced generation of reactive oxygen species (ROS), and up‐regulated mitochondrial oxidative stress within 0.5 h. Co‐administration of the ROS inhibitor NAC reversed the suppressed cell viability and colony‐forming ability, and abolished the increased level of γ‐H2A.X in the cells with the combined treatment, indicating that the enhanced ROS was involved in the anti‐proliferative effect of the combined treatment. Overall, the results demonstrated that doxycycline may function as chemosensitizers by inducing an acute and lethal ROS production to enhance cytotoxic of polyphyllin G in osteosarcoma cell lines, and the combined use of drugs may provide an alternative thinking for the development of new therapeutic agents. [ABSTRACT FROM AUTHOR]

Carvacrol is a monoterpenoid phenol that has excellent antimicrobial, antiviral, and anti-inflammatory activities. It can also improve wound healing. However, few studies have explored its antitumor effect on osteosarcoma. In this report, we tried to determine the potential efficacy of carvacrol against osteosarcoma cell lines. Our data revealed that carvacrol exposure inhibited the proliferation of osteosarcoma HOS and U-2 OS cells. In addition, carvacrol exposure enhanced the levels of cleaved PARP and caspase 3 and increased annexin V-positive cells, indicating that carvacrol exposure triggers apoptosis in osteosarcoma cell lines. Furthermore, the levels of reactive oxygen species (ROS) were enhanced after carvacrol exposure and cotreatment with NAC, the ROS scavenger, decreased the levels of cleaved PARP and caspase 3, suggesting the involvement of ROS in carvacrol-induced apoptosis. Importantly, we found that carvacrol exposure triggered several protein expressions related to endoplasmic reticulum (ER) stress, including GRP78/Bip, IRE1a, PERK, and CHOP, in HOS and U-2 OS cells, indicating that carvacrol exposure could result in ER stress in these cell lines. Cotreatment with the ER stress inhibitor 4-PBA increased the levels of cleaved PARP and caspase 3 and further suppressed cellular proliferation in carvacrol-exposed osteosarcoma cell lines. Overall, the results indicate that induced ER stress can protect cells from apoptosis, but increased ROS contributes to apoptosis in carvacrol-treated cells. In this report, we first demonstrate the role of ER stress in carvacrol-induced apoptosis and suggest that ER stress could be targeted to enhance the antitumor activity of carvacrol in osteosarcoma cell lines. [ABSTRACT FROM AUTHOR]

In this study, guaiacolate derivatives‐containing tetranuclear sodium catalysts were synthesized, and their catalytic activity in l‐lactide (LA) polymerization was evaluated. Using LBF‐Na (sodium complex bearing 2,3‐dihydro‐2,2‐dimethyl‐7‐benzofuranolate) as a catalyst, the polymerization of LA was studied in various solvents. LBF‐Na polymerized LA in dichloromethane, tetrahydrofuran, and toluene, and the catalytic activity of LBF‐Na was similar in these solvents. Among the sodium complexes, LOH‐Na (sodium complex bearing guaiacolate) exhibited higher catalytic activity (5 min, conversion = 93%; MnGPC = 7200) than the other tetranuclear sodium complexes. Furthermore, LOH‐Na exhibited an "immortal" property after 20 equivalents of benzyl alcohol loading during LA polymerization and good controllability in polylactide production. Thus, guaiacolate ligands increase the catalytic activity of sodium catalysts in LA polymerization in both coordinating and halogen‐containing solvents and under the condition of extra alcohol loading. [ABSTRACT FROM AUTHOR]

Bayer color filter array (CFA) images are captured by a single-chip image sensor covered with a Bayer CFA pattern which has been widely used in modern digital cameras. In the past two decades, many compression methods have been proposed to compress Bayer CFA images. These compression methods can be roughly divided into the compression-first-based (CF-based) scheme and the demosaicing-first-based (DF-based) scheme. However, in the literature, no review article for the two compression schemes and their compression performance is reported. In this article, the related CF-based and DF-based compression works are reviewed first. Then, the testing Bayer CFA images created from the Kodak, IMAX, screen content images, videos, and classical image datasets are compressed on the Joint Photographic Experts Group-2000 (JPEG-2000) and the newly released Versatile Video Coding (VVC) platform VTM-16.2. In terms of the commonly used objective quality, perceptual quality metrics, the perceptual effect, and the quality–bitrate tradeoff metric, the compression performance comparison of the CF-based compression methods, in particular the reversible color transform-based compression methods and the DF-based compression methods, is reported and discussed. [ABSTRACT FROM AUTHOR]

Substantially to increase the efficiency of dye‐sensitized solar cells (DSSCs), it has been fabricated with the polymer gel electrolytes (PGEs) by replacing the liquid electrolytes (LEs). Poly (ε‐caprolactone) (PCL) has been synthesized as a crystalline solid biopolymer of about 74% yield using different 6‐membered ring phenolate Al complexes. As prepared PCL was blended with LE used in dye‐sensitized solar cells (DSSCs) to prepare high polydispersity index (PDI) PGE. The prepared PGE shows cross‐linking between carboxyl and hydroxyl groups and interacts with iodide ions to form a chelate complex structure. The PGE was well‐characterized using various analytical tools to demonstrate its structural and surface morphology. The fabricated DSSCs using PGE showed high ionic conductivity (7.76 × 10−4 S cm−1), good tri‐iodide diffusion (2.052 × 10−6 Cm2 S−1), and a highly stable incident photon‐to‐current conversion efficiency (PCE; 5.92%) under solar light illumination (85 mW cm−2). Besides found PGE has improved long‐term stability up to 15 days, and these results proved that the prepared PGE is superior compared to other reported PGEs. [ABSTRACT FROM AUTHOR]

The success of many computer vision and pattern recognition applications depends on matching local features on two or more images. Because the initial correspondence set—i.e., the set of the initial feature pairs—is often contaminated by mismatches, removing mismatches is a necessary task prior to image matching. In this paper, we first propose a fast geometry histogram-based (GH-based) mismatch removal strategy to construct a reduced correspondence set C r e d u c e d , G H from the initial correspondence set C i n i . Next, we propose an effective cooperative random sample consensus (COOSAC) method for remote sensing image matching. COOSAC consists of a RANSAC, called R A N S A C i n i working on C i n i , and a tiny RANSAC, called R A N S A C t i n y , G H working on a randomly selected subset of C r e d u c e d , G H . In R A N S A C t i n y , G H , an iterative area constraint-based sampling strategy is proposed to estimate the model solution of C t i n y , G H until the specified confidence level is reached, and then R A N S A C i n i utilizes the estimated model solution of C t i n y , G H to calculate the inlier rate of C i n i . COOSAC repeats the above cooperation between R A N S A C t i n y , G H and R A N S A C i n i until the specified confidence level is reached, reporting the resultant model solution of C i n i . For convenience, our image matching method is called the GH-COOSAC method. Based on several testing datasets, thorough experimental results demonstrate that the proposed GH-COOSAC method achieves lower computational cost and higher matching accuracy benefits when compared with the state-of-the-art image matching methods. [ABSTRACT FROM AUTHOR]

Objective: To assess the healthcare utilization, economic burden, and long-term neurological complications and mortality of an adult population with Japanese encephalitis (JE). Methods: This study utilized two nationwide datasets in Taiwan: the Notifiable Disease Dataset of confirmed cases from the Centers for Disease Control to identify JE patients, and the National Health Insurance Research Database to obtain patients' healthcare utilization. Survival analyses were performed to identify prognostic factors associated with the all-cause mortality of patients. Results: This study included 352 adult cases with JE (aged≥20 years). The mean age of JE patients was 45 years. Stroke (event rate: 3.49/100 person-years) was the most common neurological complication, followed by epilepsy/convulsions (3.13/100 person-years), encephalopathy/delirium (2.20/100 person-years), and parkinsonism (1.97/100 person-years). Among the 336 hospitalized patients at JE diagnosis, 58.33% required intensive care. Among 79 patients who died following JE diagnosis, 48.84% of death events occurred within the year of diagnosis. The medical costs increased considerably at JE diagnosis and subsequent-year costs remained significantly higher than the costs before diagnosis (p<0.05). Having a four-dose JE vaccination (i.e., born after 1976) versus no JE vaccination history (i.e., born before 1963) was significantly associated with lower all-cause mortality (hazard ratio: 0.221 [95% confidence interval: 0.067, 0.725]). Comorbid diabetes and incident epilepsy/convulsion events significantly increased the mortality risk by 2.47- and 1.85-fold, respectively (p<0.05). Conclusion: A considerable medical burden associated with JE was observed in affected adults, even in the years following JE diagnosis. Vaccination should be considered to prevent this sporadic, but lethal, viral infection. Author summary: The epidemiology of adulthood Japanese encephalitis (JE) remains limited, and data on the economic burden associated with JE is lacking. This study is the first to comprehensively examine the healthcare burden (i.e., healthcare utilization and costs, neurological complications, all-cause mortality) of an adult population with JE, utilizing a nationwide cohort of JE-infected adults with up to 16 years of follow-up. In the first 6 months following JE diagnosis, a higher rate of neurological disorders was found, compared to the years after the diagnosis, with stroke being the most common neurological complication, followed by epilepsy/convulsions. The healthcare utilization of JE patients was higher in the first 6 months after the diagnosis compared to the years following the diagnosis. Medical costs increased considerably at JE diagnosis and subsequent-year costs after diagnosis remained higher than the cost before diagnosis. Having comorbid diabetes or incident epilepsy/convulsion events was a significant risk factor for mortality of adults with JE. Being born after 1976 in Taiwan, and thus likely receiving a four-dose schedule of vaccination, was associated with reduced mortality. Therefore, special attention is required for JE patients with comorbid diabetes or incident epilepsy/convulsion events, and JE vaccination should be considered to prevent this sporadic but lethal viral infection. [ABSTRACT FROM AUTHOR]

Carbodicarbene (CDC), unique carbenic entities bearing two lone pairs of electrons are well‐known for their strong Lewis basicity. We demonstrate herein, upon introducing a weak Brønsted acid benzyl alcohol (BnOH) as a co‐modulator, CDC is remolded into a Frustrated Lewis Pair (FLP)‐like reactivity. DFT calculation and experimental evidence show BnOH loosely interacting with the binding pocket of CDC via H‐bonding and π‐π stacking. Four distinct reactions in nature were deployed to demonstrate the viability of proof‐of‐concept as synergistic FLP/Modulator (CDC/BnOH), demonstrating enhanced catalytic reactivity in cyclotrimerization of isocyanate, polymerization process for L‐lactide (LA), methyl methacrylate (MMA) and dehydrosilylation of alcohols. Importantly, the catalytic reactivity of carbodicarbene is uniquely distinct from conventional NHC which relies on only single chemical feature of nucleophilicity. This finding also provides a new spin in diversifying FLP reactivity with co‐modulator or co‐catalyst. [ABSTRACT FROM AUTHOR]

Aims/Introduction: To estimate preference‐based measures of health‐related quality of life associated with sociodemographic and clinical characteristics in type 2 diabetes patients. Materials and Methods: Individuals with EuroQol‐5 dimensions‐3 levels data were identified from Taiwan's National Health Interview Survey in 2009 and 2013. Status of diabetes, comorbidities, complications and treatments were ascertained through data linkage to Taiwan's National Health Insurance Research Database. Multivariable ordinary least squares, Tobit and median regression analyses were used to estimate the coefficients that represented independent impacts of patients' characteristics on health‐related quality of life. Results: The mean health utility score for 2,104 participants was 0.838. Being female, aging, divorced/widowed, never worked or underweight, or having a lower monthly household income, injectable glucose‐lowering therapy, comorbid connective tissue disease or depression were associated with lower health utilities. Having an amputation led to the largest reduction by 0.288 in health utilities, followed by debilitating stroke (0.266), heart failure (0.237), other coronary heart disease (0.185), kidney dialysis/transplant (0.148), coronary revascularizations (0.093), transient ischemic attack/stroke (0.078), diabetic neuropathy (0.062), polyneuropathy (0.055) and other neuropathy (0.043). Conclusions: Major vascular complications, connective tissue disease and depression are associated with considerably worse health‐related quality of life. These health utility estimates can facilitate health economic evaluations to determine cost‐effective strategies for diabetes management. [ABSTRACT FROM AUTHOR]

Understanding the water state in Nafion is not only crucial for operating a proton-exchange membrane (PEM)-based fuel cell, but also intimately related to the elucidation of the proton transport mechanism in a PEM. Although many studies have been published on this subject, some controversies and ambiguities remain unresolved. In this work, we design three different types of Nafion samples by substituting protons with lithium or sodium cations. We also pay special attention to the preparation of samples for carrying out broad-range variable temperature solid state NMR experiments so that no membrane dehydration occurs during the long experimental time at low temperatures. With these precautions and improvements, clear and largely straightforward information could be obtained to ensure minimal ambiguity and complexity in the interpretation of the experimental data. Our results show that about 40–60% of water remains unfrozen at −70 °C, depending on the type of the substituting cation. Both the 1H and 2H spectral and relaxation results indicate that water freezing starts from the center of the nanopores inside Nafion and increases gradually as the temperature decreases. The protons remain dissociated with sulfonate groups even at the lowest temperature we reached (−70 °C), whereas both lithium and sodium are associated with sulfonate groups at most temperatures below 0 °C. The experimental data also suggest that besides frozen and unfrozen water, there is broad distribution of water state and dynamics in Nafion as the temperature is lowered from above zero down to −70 °C. The effect of the size of the substituting cation significantly affects the properties of supercooled water by modifying the cation–water interaction and impeding the rotation of sulfonate groups. These novel results not only help us in establishing a better understanding of the water state in Nafion and its performance as a proton exchange mebrane, but also provide insights into water freezing, antifreeze and supercooling in other nanoscopic environments. [ABSTRACT FROM AUTHOR]