Ambient Phosphor with High Efficiency and Long Lifetime in Poly(Methyl Methacrylate) Through Charge-Transfer-Mediated Triplet Exciton Formation for Photolithography Applications.

Currently, purely organic compounds showing ambient phosphorescence with high efficiency (ΦP ) and ultra-long lifetime (τP ) are quite rare and often need to be achieved in hydrophilic poly(vinyl alcohol)-based hosts. This severely limits their applications. Here, we provide a solution to this issue by constructing an ortho-linked donor-acceptor (D-A) dyad whose D moiety has not only a long-lived T1 state to achieve a long τP , but also a Tn state that is close to the S1 state of the dyad to trigger effective spin-orbit charge transfer intersystem crossing (SOCT-ISC). The rationality of this strategy was validated by a new phosphor OF-BCz that is able to show a τP of 1.92 s and a ΦP of 30 % even in a less rigid matrix of poly(methyl methacrylate) (PMMA). Excitingly, OF-BCz exhibited its potential as both a photocuring initiator and an in situ quality indicator, allowing for the visual detection of defects in photolithographic patterning.

Acquiring Charge-Transfer-Featured Single-Molecule Ultralong Organic Room Temperature Phosphorescence via Through-Space Electronic Coupling.

Although long-lived triplet charge-transfer (3 CT) state with high energy level has gained significant attention, the development of organic small molecules capable of achieving such states remains a major challenge. Herein, by using the through-space electronic coupling effect, we have developed a compound, namely NIC-DMAC, which has a long-lived 3 CT state at the single-molecule level with a lifetime of 210 ms and a high energy level of up to 2.50 eV. Through a combination of experimental and computational approaches, we have elucidated the photophysical processes of NIC-DMAC, which involve sequential transitions from the first singlet excited state (S1 ) that shows a 1 CT character to the first triplet excited state (T1 ) that exhibits a local excited state feature (3 LE), and then to the second triplet excited state (T2 ) that shows a 3 CT character (i.e., S1 (1 CT)→T1 (3 LE)→T2 (3 CT)). The long lifetime and high energy level of its 3 CT state have enabled NIC-DMAC as an initiator for photocuring in double patterning applications.

Bio-orthogonal Toolbox for Monitoring Nitric Oxide in Targeted Organelles of Live Cells and Zebrafishes.

Nitric oxide (NO), playing crucial roles as a cellular messenger and as a toxic ROS, is highly related to the physiological and pathological states of living systems. The very wide but very uneven distribution of this radical gas in the inhomogeneous biological microenvironment imposes big challenges for specifically detecting its local level in certain subcellular areas, which calls for a long list of NO probes for each target. In order to simplify the syntheses and designs of these probes, herein it is proposed to construct a versatile NO-sensing toolbox based on a bio-orthogonal concept, i.e., inverse electron demand Diels-Alder click reaction between tetrazine and strained alkyne BCN. On the one hand, rhodamine-o-phenylenediamine as the NO-responsive scaffold is coupled with a tetrazine unit to generate a general probe TMR-Tz-NO, which, to our knowledge, is the first case of the tetrazine-coupled analyte-responsive probe. On the other hand, the BCN moiety is connected to different targeting groups, such as TPP, morpholine, and Ac4ManN, targeting to mitochondria, lysosomes, and membranes, respectively. It works well to use TMR-Tz-NO to match with any targetable BCN counterpart in this toolbox to achieve the imaging of NO in the corresponding subcellular area. For example, through metabolism, Ac4ManN-BCN is effectively taken and grows on the cell membranes. The bio-orthogonal reaction between TMR-Tz-NO and Ac4ManN-BCN makes the NO probe anchored to the membrane surface permanently. The zebrafish experiment revealed that this bio-orthogonal pair can track and image the NO produced during inflammation in vivo.

Physicochemical and functional properties of the muscle protein fraction of Hypomesus olidus.

The physicochemical and functional properties of myofibrillar protein (MP), sarcoplasmic protein (SP), and myostromin (MY) in Hypomesus olidus muscle were evaluated and reported in this study. These fractions are rich in Glu. Three proteins exhibited significantly different morphologies, colors, and particle sizes. The main protein bands of MP, SP, and MY are 15-220 kDa, 26-60 kDa, and 15-245 kDa, respectively. In particular, MP is more hydrophobic. Three proteins exhibited a maximum UV absorption peak at 270 nm, and all amide I secondary structures were shown to be composed of repetitive units (e.g., α-helices and ß-sheets). The three proteins demonstrated a predominantly amorphous halo, with Td values of 52.22 °C, 59.16 °C, and 58.09 °C. Regarding their properties in water/oil absorption, emulsification, and foaming, MP is the most preferred, followed by SP and MY. In conclusion, Hypomesus olidus muscle proteins are novel and potential functional nutrition ingredients for the food industry.

A Golgi-targeted viscosity rotor for monitoring early alcohol-induced liver injury.

We proposed to monitor the early stage of alcohol-induced liver injury through quantitatively detecting Golgi viscosity. Therefore, the first Golgi-targeted fluorescent rotor (GA-Vis) was developed. With the aid of GA-Vis, the changes in Golgi viscosity during alcohol-induced liver injury were quantitatively evaluated by fluorescence lifetime imaging in live cells and zebrafish. GA-Vis was qualified as a practical tool for future diagnoses of alcohol-induced liver injury.

Fabrication and Characterization of Degradable Crop-Straw-Fiber Composite Film Using In Situ Polymerization with Melamine-Urea-Formaldehyde Prepolymer for Agricultural Film Mulching.

Soil mulch composite films composed of biodegradable materials are being increasingly used in agriculture. In this study, mulch films based on wheat straw fiber and an environmentally friendly modifier were prepared via in situ polymerization and tested as the ridge mulch for crops. The mechanical properties of the straw fiber film were significantly enhanced by the modification. In particular, the films exhibited a noticeable increase in dry and wet tensile strength from 2.35 to 4.15 and 0.41 to 1.51 kN/m, respectively, with increasing filler content from 0% to 25%. The contact angle of the straw also showed an improvement based on its hydrophilicity. The crystallinity of the modified film was higher than that of the unmodified film and increased with modifier content. The changes in chemical interaction of the straw fiber film were determined by Fourier transform infrared spectroscopy, and the thermal stability of the unmodified film was improved by in situ polymerization. Scanning electron microscopy images indicated that the modifier was uniformly dispersed in the fiber film, resulting in an improvement in its mechanical properties. The modified straw fiber films could be degraded after mulching for approximately 50 days. Overall, the superior properties of the modified straw fiber film lend it great potential for agricultural application.

Visible-light-driven photocatalytic disinfection by S-scheme α-Fe2O3/g-C3N4 heterojunction: Bactericidal performance and mechanism insight.

High-performance photocatalytic applications require to develop heterostructures between two semiconductors with matched band energy levels to facilitate charge-carrier separation. The S-scheme photocatalytic system has great potential to be explored, in terms of the improvement of charge separation, however, small efforts have been made in photocatalytic disinfection application. In this study, a non-toxic and low-cost S-scheme photocatalytic system composed of α-Fe2O3 and g-C3N4 was fabricated by in-suit production of g-C3N4 and firstly applied into water disinfection. The α-Fe2O3/g-C3N4 junction demonstrated an enhanced activity for photocatalytic bacterial inactivation, with the complete inactivation of 7 log10 cfu·mL-1 of Escherichia coli K-12 cells within 120 min under visible light irradiation. Its logarithmic bacterial inactivation efficiency was nearly 7 times better than that of single g-C3N4. The experimental results suggested that the effective prevention of charge-carrier recombination led to an improved generation of reactive oxygen species (ROSs), resulting in impressive disinfection performance. Moreover, the DNA gel electrophoresis experiments validated the reason for the irreversible death of bacteria, which was the leakage and destruction of chromosomal DNA. In addition, this S-scheme heterojunction also showed excellent photocatalytic disinfection performance in authentic water matrices (including tap water, secondary treated sewage effluent, and surface water) under visible light irradiation. Hence, the α-Fe2O3/g-C3N4 composite has great potential for sustainable and efficient photocatalytic disinfection applications.

Preparation of metal-free BP/CN photocatalyst with enhanced ability for photocatalytic tetracycline degradation.

The successful application of photocatalysis in practical water treatment opreations relies greatly on the development of highly efficient, stable and low-cost photocatalysts. The low-cost metal-free photocatalyst made up of black phosphorus (BP) and graphitic carbon nitride (CN) was successfully constructed and firstly used for the photocatalytic treatment of antibiotic contaminants in this work. Compared with bare CN, the BP/CN photocatalyst exhibited the enhanced photocatalytic performance for tetracycline hydrochloride (HTC) degradation, that 99% of HTC was removed by 6BP/CN (doping amount of BP was 6%) within 30 min under the simulated visible-light irradiation. The efficiency was even comparable to those of some high-efficiency photocatalysts recently-reported such as Fe0@POCN, CuInS2/Bi2MoO6 and Cu2O@HKUST-1. Under natural sunlight illumination, the determined apparent rate constant for degradation of HTC by BP/CN was 2.7 times as that by P25 TiO2. The experimental results indicated that loading BP on CN could enhance the separation of charge carriers and promote the ability of light absorption for visible-light, thus leading to a greater catalytic activity. Meanwhile, the influences of different operating variables (pH, water, ion and HTC concentration) on HTC degradation were studied in detail. Furthermore, the degradation pathway of HTC was also proposed. In addition, the photocatalytic activity of the BP/CN for production of hydrogen peroxide (H2O2) was also studied, which could reach up to 501.04 µmol g-1h-1. It is anticipated that BP/CN photocatalyst could be used for practical water treatment.

Losartan inhibits hyposmotic-induced increase of IKs current and shortening of action potential duration in guinea pig atrial myocytes.

OBJECTIVE: The present study aims to investigate the effect of losartan, an selective angiotensin II type 1 receptor (AT1R) blocker, on both the increase of IKs current and shortening of action potential duration (APD) induced by stretch of atrial myocytes, and to uncover the mechanism underlying the treatment of fibrillation (AF) by AT1R blockers. METHODS: Hyposmotic solution (Hypo-S) was applied in the guinea pig atrial myocytes to simulate cell stretch, then patch-clamp technique was applied to record the IKs and APD in atrial myocytes. RESULTS: Hypo-S increased the IKs by 105.6%, while Hypo-S+1-20 µM of losartan only increased the IKs by 70.3-75.5% (p<0.05 vs. Hypo-S). Meanwhile, Hypo-S shortened APD90 by 20.2%, while Hypo-S+1-20 µM of losartan shortened APD90 by 13.03-14.56% (p<0.05 vs. Hypo-S). CONCLUSION: The above data indicate that the effect of losartan on the electrophysiological changes induced by stretch of atrial myocytes is associated with blocking of AT1 receptor, and is beneficial for the treatment of AF that is often accompanied by the expansion of atrial myocytes and the increase of effective refractory period.

Enhancing amplification of late-outgrowth endothelial cells by bilobalide.

Transfusion of autologous late-outgrowth endothelial cells (OECs) is a promising treatment for restenosis after revascularization. Preparing cells by in vitro amplification is a key step to implement the therapy. This study aimed to demonstrate that bilobalide, a terpenoid, enhances the OEC amplification. Human-, rabbit- and rat OECs and a mouse femoral artery injury model were used. Expanding OECs used endothelial growth medium-2 as the standard culture medium while exploring the mechanisms used endothelial basal medium-2. Proliferation assay used MTT method and BrdU method. Migration assay used the modified Boyden chamber. Intracellular nitric oxide, superoxide anion, hydroxyl radical/peroxynitrite and H2 O2 were quantified with DAF-FM DA, dihydroethidium, hydroxyphenyl fluorescein and a H2 O2 assay kit, respectively. Activated ERK1/2 and eNOS were tested with the Western blot. Bilobalide concentration-dependently enhanced OEC number increase in vitro. Transfusion of bilobalide-based human OECs into femoral injured athymia nude mouse reduced the intimal hyperplasia. Bilobalide promoted OEC proliferation and migration and increased the intracellular nitric oxide level. L-NAME, a NOS inhibitor, inhibits but not abolishes OEC proliferation, migration and ERK1/2 activation. Bilobalide concentration-dependently enhanced the eNOS Ser-1177 phosphorylation and Thr-495 dephosphorylation in activated OECs. Bilobalide alleviates the increase in hydroxyl radical/peroxynitrite, superoxide anion and H2 O2 in proliferating OECs. In conclusion, nitric oxide plays a partial role in OEC proliferation and migration; bilobalide increases OEC nitric oxide production and decreases nitric oxide depletion, promoting the OEC number increase; Bilobalide-based OECs are active in vivo. The findings may simplify the preparation of OECs, facilitating the implementation of the autologous-OECs-transfusion therapy.

Characterization of Secondary Metabolites from Purple Ipomoea batatas Leaves and Their Effects on Glucose Uptake.

Ipomoea batatas has long been used in folk medicine for the treatment of hyperglycemia or as a food additive for the prevention of type 2 diabetes. However, neither the plant extract nor its active components have been evaluated systematically. In this work four crude extracts, including n-hexane- (IBH), 95% MeOH- (IBM), n-BuOH- (IBB), and H2O-soluble (IBW) fractions, were prepared by fractionation of a methanolic extract of purple I. batatas leaves. Twenty-four pure compounds 1-24 were then isolated by various chromatographic techniques and their structures identified from NMR and MS data. Glucose uptake assays in differentiated 3T3-L1 adipocytes and rat primary hepatocytes, as well as western blot analysis, were carried out to evaluate the antidiabetic activity of this species. The IBH crude fraction, with methyl decanoate (22) as a major and active compound, showed the greatest effect on glucose uptake, most likely via activation of Glut4 and regulation of the PI3K/AKT pathway. Quercetin 3-O-ß-d-sophoroside (1), quercetin (3), benzyl ß-d-glucoside (10), 4-hydroxy-3-methoxybenzaldehyde (12), and methyl decanoate (22) could be important components contributing to the antidiabetic effects. We conclude that purple I. batatas leaves have potential as an antidiabetic plant source and the active constituents 1, 3, 10, 12, and 22 are promising lead candidates for future investigation.

[Simulation of vegetation indices optimizing under retrieval of vegetation biochemical parameters based on PROSPECT + SAIL model].

This study analyzed the sensitivities of three vegetation biochemical parameters [chlorophyll content (Cab), leaf water content (Cw), and leaf area index (LAI)] to the changes of canopy reflectance, with the effects of each parameter on the wavelength regions of canopy reflectance considered, and selected three vegetation indices as the optimization comparison targets of cost function. Then, the Cab, Cw, and LAI were estimated, based on the particle swarm optimization algorithm and PROSPECT + SAIL model. The results showed that retrieval efficiency with vegetation indices as the optimization comparison targets of cost function was better than that with all spectral reflectance. The correlation coefficients (R2) between the measured and estimated values of Cab, Cw, and LAI were 90.8%, 95.7%, and 99.7%, and the root mean square errors of Cab, Cw, and LAI were 4.73 microg x cm(-2), 0.001 g x cm(-2), and 0.08, respectively. It was suggested that to adopt vegetation indices as the optimization comparison targets of cost function could effectively improve the efficiency and precision of the retrieval of biochemical parameters based on PROSPECT + SAIL model.

[Effects of ethanol on action potential of rat myocardium and human Kv1.5 channel].

The purpose of the present study was to investigate the effects of different concentrations of ethanol on action potential (AP) in the isolated rat myocardium and the possible mechanism of electric-physiological changes. Standard microelectrode technique was used to record AP in isolated rat myocardium, and whole cell patch clamp technique was used to record the human Kv1.5 (hKv1.5) channel currents in HEK293 cells. The effects of different concentrations of ethanol (6.25, 12.5, 25.0, 50.0, 100.0 and 200.0 mmol/L) on AP parameters in rat atrium and papillary and Kv1.5 channel currents in HEK293 cells were analyzed. The results showed that in isolated atrium, action potential amplitude (APA), action potential duration (APD), action potential duration of 50% repolarization (APD(50)) and action potential duration of 90% repolarization (APD(90)) were not affected by 6.25 and 12.5 mmol/L ethanol, while APD, APD(50) and APD(90) were prolonged significantly by 25.0-200.0 mmol/L ethanol (P < 0.05 or P < 0.01), and APA was reduced with 100.0 and 200.0 mmol/L ethanol (P < 0.05 or P < 0.01). In isolated papillary, APA, APD, APD(50) and APD(90) were not affected by 6.25-25.0 mmol/L ethanol, while APD, APD(50) and APD(90) were prolonged significantly with 50.0-200.0 mmol/L ethanol (P < 0.05 or P < 0.01), and APA was reduced with 200.0 mmol/L ethanol (P < 0.05). The Kv1.5 channel currents were inhibited by ethanol in a concentration dependent manner in HEK293 cells. These findings suggest that 6.25 and 12.5 mmol/L ethanol produce no effects on AP parameters, and 50.0-200.0 mmol/L ethanol prolong APD significantly in isolated rat atrium and papillary. The prolonged effect on APD in isolated myocardium may be due to the inhibition of the Kv1.5 channel currents.

Transfusion of autologous late-outgrowth endothelial cells reduces arterial neointima formation after injury.

AIMS: Late-outgrowth endothelial cells (OECs) exist in blood and other organs. We aimed to explore whether and how OECs participate in re-endothelialization and prevent vascular neointima formation after injury. METHODS AND RESULTS: Rabbit bone marrow OECs were cultured for 4 weeks to increase their numbers. Transfusion of autologous OECs (2 × 106-1 × 107/kg) soon after rabbit ear central artery injury reduced the increase in intima area and the decrease in lumen area observed at days 14 and 28. Transfusion of autologous OECs (1 × 107/kg) ameliorated some early (days 2 and 7) inflammatory and angiogenic responses (local and systemic) to the injury. Red fluorescence was seen within 7 days after transfusion of 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine-labelled acetylated low-density lipoprotein (Dil-acLDL)-incorporated OECs, and 1 h after perfusion of the isolated rabbit ear with Ringer-Locke solution containing Dil-acLDL-incorporated OECs, in the injured rabbit ear central artery. After transfusion of 5-bromo-2'-deoxyuridine (BrdU) incorporated autologous OECs, BrdU-positive cells appeared in the injured artery intima at day 3 and were present in the rescued artery endothelium at day 28. The OECs, ranging from 5%-15% of vascular smooth muscle cells (VSMCs), and the OEC-conditioned medium (5-15%) both inhibited VSMC proliferation and migration in vitro and regulated the arrangement of VSMCs. The VSMCs were helpful for OECs to form tubes in vitro. CONCLUSION: Circulating OECs participate in re-endothelialization directly and inhibit VSMC migration and proliferation by a paracrine pathway; transfusion of large numbers of autologous OECs soon after vascular injury may prevent neointima formation.

Caulophine protects cardiomyocytes from oxidative and ischemic injury.

Caulophine is a new fluorenone alkaloid isolated from the radix of Caulophyllum robustum MAXIM and identified as 3-(2-(dimethylamino) ethyl)-4,5-dihydroxy-1,6-dimethoxy-9H-fluoren-9-one. Due to its new chemical structure, the pharmacological activities of caulophine are not well characterized. The present study evaluated the protective effect and the primary mechanisms of caulophine on cardiomyocyte injury. Viability of cardiomyocytes was assayed with the MTT method, and cell apoptosis was detected by flow cytometry. Myocardial infarction was produced by ligating the coronary artery, and myocardial ischemia was induced by isoproterenol in rats. Myocardial infarction size was estimated with p-nitro-blue tetrazolium staining. Lactate dehydrogenase (LDH), creatine kinase (CK), superoxide dismutase (SOD), malondialdehyde (MDA), and free fatty acid (FFA) were spectrophotometrically determined. Histopathological and ultrastructural changes of ischemic myocardium were observed. The results showed that pretreatment with caulophine increased the viability of H(2)O(2)- and adriamycin-injured cardiomyocytes; decreased CK, LDH, and MDA; increased SOD; and inhibited H(2)O(2)-induced cellular apoptosis. Caulophine reduced myocardial infarct size and serum CK, LDH, FFA, and MDA; raised serum SOD; and improved histopathological and ultrastructural changes of ischemic myocardium. The results demonstrate that caulophine has the ability to protect cardiomyocytes from oxidative and ischemic injury through an antioxidative mechanism that provides a basis for further study and development of caulophine as a promising agent for treating coronary heart disease.

Effects of caulophine on caffeine-induced cellular injury and calcium homeostasis in rat cardiomyocytes.

Caulophine is a novel fluorenone alkaloid isolated from the radix of Caulophyllum robustum Maxim. Caulophine showed high affinity for the rat myocardial cell membrane as assessed by cell membrane chromatography, suggesting that the compound may exert bioactivity in the heart. It is known that calcium plays an important role in the pathogenesis of ischaemic heart disease, and caffeine can cause calcium overload in cardiomyocytes by inducing calcium release from the sarcoplasmic reticulum. Therefore, the present study evaluated the effects of caulophine on caffeine-induced injury and calcium homeostasis in cardiomyocytes. Cardiomyocytes were pre-treated with caulophine before exposure to caffeine or potassium chloride (KCl). Cell viability was assayed using the MTT method, and lactate dehydrogenase (LDH) and malondialdehyde (MDA) were measured spectrophotometrically. Caulophine-pre-treated cardiomyocytes were incubated with Fluo-3/AM, and then caffeine or KCl was used to induce Ca(2+) overload. The total intracellular Ca(2+) concentration was measured by flow cytometry. Fluorescence densities of single cardiomyocytes were detected using a confocal microscope. Caulophine increased the viability of caffeine-injured cardiomyocytes and decreased LDH activity and MDA level in cardiomyocytes. Furthermore, caulophine significantly decreased the total intracellular free Ca(2+) concentration and intracellular calcium release in cardiomyocytes in response to caffeine. However, the same concentrations of caulophine did not affect KCl-induced calcium influx. Our results suggest that caulophine protects cardiomyocytes from caffeine-induced injury as a result of calcium antagonism. This finding provides a basis for further study and development of caulophine as a new calcium antagonist for treating ischaemic cardiovascular diseases.

PPARalpha activator fenofibrate modulates angiotensin II-induced inflammatory responses in vascular smooth muscle cells via the TLR4-dependent signaling pathway.

Angiotensin II (Ang II) is a crucial contributor to inflammatory processes involved in development and progression of atherosclerotic lesion. Toll-like receptor 4 (TLR4) signaling responsible for the initiation of inflammation also participates in pathogenesis of atherosclerosis. The protective effect of peroxisome proliferator-activated receptor alpha (PPARalpha) activators on atherosclerosis may be due to their impact on vascular inflammation, plaque instability and thrombosis. However, mechanisms underlying the inhibitory effects of PPARalpha activators on Ang II-induced vascular inflammation and the TLR4-dependent signaling pathway involved in vascular smooth muscle cells (VSMCs) remain unclear. The present study demonstrated that PPARalpha activator fenofibrate decreased Ang II-induced generation of pro-inflammatory mediators such as TLR4, MMP-9 and TNF-alpha, but enhanced production of anti-inflammatory molecules like PPARalpha and 6-keto-PGF(1alpha) both in vivo and in vitro. Meanwhile, treatment of VSMCs with the TLR4 inhibitor or TLR4 siRNA showed that the inhibitory effects of fenofibrate on Ang II-induced inflammatory responses in VSMCs were dependent on TLR4. Furthermore, fenofibrate depressed Ang II-induced inflammatory responses in VSMCs by intervening the downstream effector molecules of the TLR4-dependent signaling pathway, including interferon-gamma inducible protein 10 (IP-10), protein kinases C (PKC) and nuclear factor kappaB (NF-kappaB). Thus, these findings provide the evidence for beneficial effects of PPARalpha activator fenofibrate to counter-regulate vascular inflammation induced by Ang II. More importantly, anti-inflammatory action of fenofibrate via interfering with the TLR4-dependent signaling pathway (TLR4/IP-10/PKC/NF-kappaB) works in concert to protect against atherosclerosis.