Role of bile acids in colon carcinogenesis

Bile acids(BAs)are cholesterol derivatives synthesized in the liver and then secreted into the intestine for lipid absorption.There are numerous scientific reports describing BAs,especially secondary BAs,as strong carcinogens or promoters of colon cancers.Firstly,BAs act as strong stimulators of colorectal cancer(CRC)initiation by damaging colonic epithelial cells,and inducing reactive oxygen species production,genomic destabilization,apoptosis resistance,and cancer stem cells-like formation.Consequently,BAs promote CRC progression via multiple mechanisms,including inhibiting apoptosis,enhancing cancer cell proliferation,invasion,and angiogenesis.There are diverse signals involved in the carcinogenesis mechanism of BAs,with a major role of epidermal growth factor receptor,and its down-stream signaling,involving mitogen-activated protein kinase,phosphoinositide 3-kinase/Akt,and nuclear factor kappa-light-chain-enhancer of activated B cells.BAs regulate numerous genes including the human leukocyte antigen class I gene,p53,matrix metalloprotease,urokinase plasminogen activator receptor,Cyclin D1,cyclooxygenase-2,interleukin-8,and miRNAs of CRC cells,leading to CRC promotion.These evidence suggests that targeting BAs is an efficacious strategies for CRC prevention and treatment.

Efficiency enhancement of fluorescent blue organic light-emitting diodes using doped hole transport and emissive layers

The electroluminescent characteristics of blue organic light-emitting diodes （BOLEDs） fabricated with doped charge carrier transport layers are analyzed. The fluorescent blue dopant BCzVBi is doped in an emissive layer, hole transport layer （HTL） and electron transport layer （ETL）, respectively, to optimize the probability of ex- citon generation in the BOLEDs. The luminance and luminous efficiency of BOLEDs made with BCzVBi-doped HTL and ETL increase by 22% and 17% from 11,683 cd/m2 at 8.5 V and 6.08 cd/A at 4.0 V to 14,264 cd/m2 at 8.5 V and 7.13 cd/A at 4.0 V while CIE coordinates of （0.15, 0.15） of both types of BOLEDs remained unchanged. The electron mobility of BCzVBi is estimated to be 1.02 × 10-5 cm2/Vs by TOF.

White phosphorescent organic light-emitting diodes using double emissive layer with three dopants for color stability

We fabricate white phosphorescent organic light-emitting diodes （PHOLEDs） with three dopants and double emissive layer （EML） to achieve color stability. The white PHOLEDs use FIrpic dopant for blue EML （B- EML）, and Ir（ppy）3：Ir（piq）3 dopants for green：red EML （GR-EML） with N,N＇-dicarbazolyl-3, 5-benzene （mCP） as host material. Thicknesses of B-EML and GR-EML are adjusted to form a narrow recombination zone at two EML＇s interface and charge trapping happens in EML according to wide highest occupied molecular orbital and/or lowest unoccupied molecular orbital energy band gap of mCP and smaller energy band gap of dopants. The total thickness of both EMLs is fixed at 30 nm in the device structure of ITO （150 nm）/MoO3 （2 nm）/N,N＇-diphenyl-N,N＇-bis（1-naphthyl-phenyl）-（1,1″-biphenyl）-4, 4＇-diamine （70 nm）/ meP：Firpic-8.0% （12 nm）/mCP：Ir（ppy）3-3.0%：Ir（piq）3-1.5% （18 nm）/2″,2＇,2＂＇-（1,3,5-benzinetriyl）-tris（1- phenyl-l-H-benzimidazole） （30 nm）/8-hydroxyquinolinolato-lithium （2 nm）/A1 （120 nm）. White PHOLED shows 18.25 cd/A of luminous efficiency and white color coordinates of （0.358 and 0.378） at 5000 cd/m2 and color stability with slight CIExy change of （0.028 and 0.002） as increasing luminance from 1000 to 5000 cd/m^2.

Realization of high-performance blue organic light-emitting diodes using multi-emissive layers

High-performance blue organic light-emitting diodes （OLEDs） are developed. A concept of using multiple-emissive layer （EML） configuration is adopted. In this letter, bis（2-methyl-8-quinolinolate）-4- （phenylphenolato）A1 （BAlq） and 9,10-di（naphtha-2-yl）anthracene （ADN）, which serve n- and p-type EMLs, respectively, are used to evaluate and demonstrate the multi-EML concept for blue OLEDs. The thickness effect of individual EMLs and the number of EMLs, e.g., triple and quadruple EML components, on the power efficiency of blue OLEDs are systematically investigated. To illustrate the point, the total thickness of the emissive region in different blue OLEDs are kept contact at 30 nm for comparison. The power efficiency of blue OLEDs with a quadruple EML structure of BAlq/ADN/BAlq/ADN is about 40% higher than that of blue OLEDs having a single EML unit. The Commission Internationale deL＇eclairage color coordinates of multi-EML OLEDs have values that represent the average of blue emissions from individual EMLs of BAlq and ADN.