Inhibitory effects of apigenin and kaempferol on the essential solute carrier transporters

AIM： To evaluate the inhibitory effects of apigenin and kaempferol on the uptake of several important solute carrier （SLC） transporters.METHODS： Various SLC transporters including the essential human organic anion transporter 1 （OAT1）, OAT2, OAT3 and OAT4 as well as the important organic cation transporter 1 （OCTN1） and OCTN2, were over-expressed in human embryonic kidney （HEK）-293 cells, a well-established cell model of transporter studies. Transport uptake assay was performed 24 h after the transfection. The transport activity was assessed with the uptake of previously determined transporter model substrates and the inhibitory effect of apigenin and kaempferol was evaluated with the substrate uptake in the presence of 10 μmol/L of each compound. Uptake measurements with varying concentrations of inhibitors （ranged from 0.0001 to 50 μmol/L） were performed to further characterize the inhibitory potency of apigenin and kaempferol. The IC50 value （the concentration that inhibits 50% of the transporter function） of each com-pound was then calculated by the nonlinear regression model of Graphpad Prism 6.0 software.RESULTS： Our data indicated that apigenin could potently inhibit the uptake of estrone-3-sulfate （ES） mediated by the HEK-293 cells expressing OAT2, OAT3 and OAT4 as well as the L-ergothioneine uptake via OCTN1-expressing HEK-293 cells. Among these trans-porters, the most prominent inhibition of apigenin was observed in the case of OAT3. Kaempferol showed sig-nifcant inhibitory effects on the uptake of ES mediated through OAT2 and OAT3. Impaired L-ergothioneine uptake due to the presence of kaempferol was also ob-served in OCTN1-expressing HEK-293 cells. Similar to apigenin, kaempferol showed the most potent inhibito-ry effect on OAT3 as well. To further assess the inhibi-tory potencies of these two compounds on the uptake of ES mediated by OAT3-expressing HEK-293 cells, their IC50 values were then determined. Both chemicals showed pronounced inhibitory potencies on OAT3 with the IC50 values of 1.7 ± 0.1 and 1.0 ± 0.1 μmol/L （P 〈 0.01） for apigenin and kaempferol, respectively.CONCLUSION： Both apigenin and kaempferol are po-tent inhibitors of OAT3; precautions will be necessary when co-administrating them with drugs that are sub-strates of OAT3.

Expression and function of renal and hepatic organic anion transporters in extrahepatic cholestasis

Obstructive jaundice occurs in patients suffering from cholelithiasis and from neoplasms affecting the pancreas and the common bile duct.The absorption,distribution and elimination of drugs are impaired during this pathology.Prolonged cholestasis may alter both liver and kidney function.Lactam antibiotics,diuretics,non-steroidal anti-inflammatory drugs,several antiviral drugs as well as endogenous compounds are classified as organic anions.The hepatic and renal organic anion transport pathways play a key role in the pharmacokinetics of these compounds.It has been demonstrated that acute extrahepatic cholestasis is associated with increased renal elimination of organic anions.The present work describes the molecular mechanisms involved in the regulation of the expression and function of the renal and hepatic organic anion transporters in extrahepatic cholestasis,such as multidrug resistanceassociated protein 2,organic anion transporting polypeptide 1,organic anion transporter 3,bilitranslocase,bromosulfophthalein/bilirubin binding protein,organic anion transporter 1 and sodium dependent bile salt transporter.The modulation in the expression of renal organic anion transporters constitutes a compensatory mechanism to overcome the hepatic dysfunction in the elimination of organic anions.

THE CLIMATE FEATURES OF THE SOUTH CHINA SEA WARM POOL

There exists a warm pool in the South China Sea (SCS). The temporal and spatial distribution and evolution of SCS warm pool is investigated using water temperatures at a depth of 20 m in the sea. The formation of the warm pool is discussed by combining water temperatures with geostrophic currents and simu-lated oceanic circulation. It is found that there are significant seasonal and interannual changes in the warm pool and in association with the general circulation of the atmosphere. The development of SCS warm pool is also closely related to the gyre activities in the sea and imported warm water from Indian Ocean (Java Sea) besides radiative warming.

^(18)F-fluoro-2-deoxyglucose uptake on PET CT and glucose transporter 1 expression in colorectal adenocarcinoma

AIM:To evaluate the correlation between the level of 18 F-fluoro-2-deoxyglucose (18 F-FDG) uptake and glucose transporter 1 (GLUT1) expression in colorectal adenocarcinoma (CRA).METHODS:Forty four patients with resected CRA and preoperative 18 F-FDG positron emission tomography computed tomography data were investigated in this study.Comparison of maximum standardized uptake value (SUVmax) of the lesion was made with GLUT1 expression by immunohistochemistry and various clinicopathologic factors including tumor volume,invasion depth,gross finding,and lymph node metastasis.RESULTS:SUVmax was 14.45 ± 7.0 in negative GLUT1 expression cases,15.51 ± 5.7 in weak GLUT1 expression cases,and 16.52 ± 6.8 in strong GLUT1 expression cases,and there was no correlation between between GLUT1 expression and SUVmax.SUVmax was significantly correlated with tumor volume (P < 0.001).However,there was no significant differences in SUVmax and GLUT1 expression among other clinicopathologic factors.CONCLUSION:GLUT1 expression does not correlates significantly with 18 F-FDG uptake in CRA.18 F-FDG uptake was increased with tumor volume,which is statistically significant.

Cavity optomechanics： Manipulating photons and phonons towards the single-photon strong coupling

Cavity optomechanical systems provide powerful platforms to manipulate photons and phonons, open potential ap- plications for modern optical communications and precise measurements. With the refrigeration and ground-state cooling technologies, studies of cavity optomechanics are making significant progress towards the quantum regime including non- classical state preparation, quantum state tomography, quantum information processing, and future quantum internet. With further research, it is found that abundant physical phenomena and important applications in both classical and quan- tum regimes appeal as they have a strong optomechanical nonlinearity, which essentially depends on the single-photon optomechanical coupling strength. Thus, engineering the optomechanical interactions and improving the single-photon optomechanical coupling strength become very important subjects. In this article, we first review several mechanisms, theoretically proposed for enhancing optomechanical coupling. Then, we review the experimental progresses on enhancing optomechanical coupling by optimizing its structure and fabrication process. Finally, we review how to use novel structures and materials to enhance the optomechanical coupling strength. The manipulations of the photons and phonons at the level of strong optomechanical coupling are also summarized.

Operation control strategy of series-parallel hydraulic hybrid vehicle

A series-parallel hydraulic hybrid system applied to public buses is put torwaro, ano parameters of key components are analyzed and determined. Energy management strategy based on logic thresh- old is designed which is aimed at efficient operation of the overall system considering the operational characteristic of the components and taking the curves of engine, hydraulic pump/motor and hydrau- lic pump as the main design basis; regenerative control strategy which makes regenerative brake sys- tem and frictional brake system work harmoniously is designed to raise recovery rate of regenerative brake energy. System dynamic modeling and simulation results show that the energy control strategy designed here is able to adapt system to changes of working condition and switch the operating mode reasonably. The regenerative braking control strategy is effective in raising the utilization of energy and improving fuel economy.

Ion and water transport in charge-modified graphene nanopores

Porous graphene has a high mechanical strength and an atomic-layer thickness that makes it a promising material for material separation and biomolecule sensing. Electrostatic interactions between charges in aqueous solutions are a type of strong long-range interaction that may greatly influence fluid transport through nanopores. In this study, molecular dynamic simulations were conducted to investigate ion and water transport through 1.05-nm diameter monolayer graphene nanopores, with their edges charge-modified. Our results indicated that these nanopores are selective to counterions when they are charged. As the charge amount increases, the total ionic currents show an increase-decrease profile while the coion currents monotonically decrease. The co-ion rejection can reach 76.5% and 90.2% when the nanopores are negatively and positively charged, respectively. The Cl-ion current increases and reaches a plateau, and the Na＋current decreases as the charge amount increases in systems in which Na＋ions act as counterions. In addition, charge modification can enhance water transport through nanopores. This is mainly due to the ion selectivity of the nanopores. Notably, positive charges on the pore edges facilitate water transport much more strongly than negative charges.

Ar^+/Ar, O_2^+/O_2 and N_2^+/N_2 Elastic Momentum Collision Cross Sections: Calculation and Validation Using the Semi-Classical Model

The aim of this paper is to obtain relevant sets of collision cross sections of the parent ions in low pressure discharges in argon, oxygen, and nitrogen, i.e., Ar＋ in Ar, O2＋ in O2 and N2＋ in N2. These ion data are first discussed and then validated from comparisons between the calculated transport coefficients and those measured in the literature. The elastic momentum transfer collision cross sections are determined from a semi-classical approximation for the phase shift calculation based on a 12-6-4 inter-particle potential while ion transport coefficients are determined versus the reduced electric field from Monte Carlo simulations.

Morphological and Physiological Responses of Plants to Cadmium Toxicity: A Review

Cadmium(Cd) contamination has posed an increasing challenge to environmental quality and food security. In recent years,phytoremediation has been particularly scrutinized because it is cost-effective and environmentally friendly, especially the use of metal-hyperaccumulating plants to extract or mine heavy metals from polluted soils. Under Cd stress, responses of hyperaccumulator and non-hyperaccumulator plants differ in morphological responses and physiological processes such as photosynthesis and respiration,uptake, transport, and assimilation of minerals and nitrogen, and water uptake and transport, which contribute to their ability to accumulate and detoxify Cd. This review aims to provide a brief overview of the recent progresses in the differential responses of hyperaccumulator and non-accumulator plants to Cd toxicity in terms of growth and physiological processes. Such information might be useful in developing phytoremediation technology for contaminated soils.

An analysis of the Circumferential Grooves Casing Treatment for transonic compressor flow

The stall mechanism of the NASA Rotor 37 is investigated through the analysis of the critical flow structures near the stall under the transonic condition. The performance of the rotor with Circumferential Grooves Casing Treatment (CGCT) is also studied based on the Reynolds-Averaging Navier-Stokes approach. The study finds that stall margin improvement can be achieved without significant penalty on the efficiency for the two CGCT configurations applied. The effects of circumferential grooves on the critical flow structures are studied through the analysis of the tip leakage mass and momentum transport that further re-veal the CGCT mechanism.