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1.
Various 2-substituted indoles were prepared by heteroannulation of o-iodoanilines and terminal alkynes in a one-pot reaction with a Pd(II)-NaY zeolite catalyst. The product formation largely depended on the solvent, base, and reaction temperature. The recycled catalyst showed good reusability in the heteroannulation reaction. 相似文献
2.
Dong‐Cheol Shin Yun‐Hi Kim Hong You Jae Gyu Jin Soon‐Ki Kwon 《Journal of polymer science. Part A, Polymer chemistry》2004,42(22):5636-5646
A poly(p‐phenylenevinylene) (PPV) derivative containing a bulky (2,2‐diphenylvinyl)phenyl group in the side chain, EHDVP‐PPV, was synthesized by Gilch route. The reduced tolane‐bisbenzyl (TBB) defects, as well as the structure of the polymer, was confirmed by various spectroscopic methods. The intramolecular energy transfer from the (2,2‐diphenylvinyl)phenyl side group to the PPV backbone was studied by UV‐vis and photoluminescence (PL) of the obtained polymer and model compound. The polymer film showed maximum absorption and emission peaks at 454 and 546 nm, respectively, and high PL efficiency of 57%. A yellow electroluminescence (λmax = 548 nm) was obtained with intensities of 6479 cd/m2 when the light‐emitting diodes of ITO/PEDOT/EHDVP‐PPV/LiF/Al were fabricated. The maximum power efficiency of the devices was 0.729 lm/W with a turn‐on voltage of 3.6 V. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 5636–5646, 2004 相似文献
3.
Lui Lam Flonnie Dowell Helmut Brand Guenter Ahlers 《Journal of statistical physics》1991,64(5-6):899-901
4.
An algorithm for a time accurate incompressible Navier–Stokes solver on an unstructured grid is presented. The algorithm uses a second order, three‐point, backward difference formula for the physical time marching. For each time step, a divergence free flow field is obtained based on an artificial compressibility method. An implicit method with a local time step is used to accelerate the convergence for the pseudotime iteration. To validate the code, an unsteady laminar flow over a circular cylinder at a Reynolds number of 200 is calculated. The results are compared with available experimental and numerical data and good agreements are achieved. Using the developed unsteady code, an interaction of a Karman vortex street with an elliptical leading edge is simulated. The incident Karman vortex street is generated by a circular cylinder located upstream. A clustering to the path of the vortices is achieved easily due to flexibility of an unstructured grid. Details of the interaction mechanism are analysed by investigating evolutions of vortices. Characteristics of the interactions are compared for large‐ and small‐scale vortex streets. Different patterns of the interaction are observed for those two vortex streets and the observation is in agreement with experiment. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
5.
Ki Sik Ha 《Semigroup Forum》1989,38(1):215-221
LetZ be a generator of an exponentially boundedC-semigroup {S
t
}
t≥0 in a Banach space and letT
t
=C
−1
S
t
. We show that the spectral mapping theorems such as exp(tσ(Z)) ⊂ σ(T
t
) and exp(tσ
p
(Z)) ⊂ tσ
p
(T
t
) ⊂ exp(tσ
p
(Z)) ⋃ {0} for everyt≥0 hold.
The present studies were supported by the Basic Science Research Institute Program, Ministry of Education, 1987. 相似文献
6.
铑(Ⅲ)-钼酸盐-罗丹明B显色体系的研究和应用 总被引:1,自引:0,他引:1
在聚乙烯醇(PVA)存在下,铑(Ⅲ)与钼酸盐和罗丹明B(RB)形成离子缔合物,缔合物的最大吸收位于580nm,摩尔吸光系数ε值1.68×105L·mol-1·cm-1,服从比耳定律范围0~10μgRh/25mL,方法用于催化剂和冶金产品中铑的测定,结果满意 相似文献
7.
Summary Real hypersurfaces of an almost Hermitian manifold naturally admit an almost contact metric structure and the (f, g, u, v, w, , , )-structure is defined on submanifolds of codimension 3 of an almost Hermitian manifold. We study the so-called semi-invariant submanifolds of a complex space form with almost contact metric compound structure which is a general notion of (f, g, u, v, w, , , )-structure.Dedicated to professor Eulyong Pak on his 60th birthdayThis research was partially supported by Korean Science and Engineering Foundation Grant. 相似文献
8.
In current clinical practice, photodynamic therapy (PDT) is carried out with prescribed drug doses and light doses as well as fixed drug-light intervals and illumination fluence rates. This approach can result in undesirable treatment outcomes of either overtreatment or undertreatment because of biological variations between different lesions and patients. In this study, we explore the possibility of improving PDT dosimetry by monitoring drug photobleaching and photoproduct formation. The study involved 60 mice receiving the same drug dose of a novel verteporfin-like photosensitizer, QLT0074, at 0.3 mg/kg body weight, followed by different light doses of 5, 10, 20, 30, 40 or 50 J/cm2 at 686 nm and a fluence rate of 70 mW/cm2. Photobleaching and photoproduct formation were measured simultaneously, using fluorescence spectroscopy. A ratio technique for data processing was introduced to reliably detect the photoproduct formed by PDT on mouse skin in vivo. The study showed that the QLT0074 photoproduct is stable and can be reliably quantified. Three new parameters, photoproduct score (PPS), photobleaching score (PBS) and percentage photobleaching score (PBS%), were introduced and tested together with the conventional dosimetry parameter, light dose, for performance on predicting PDT-induced outcome, skin necrosis. The statistical analysis of experimental results was performed with an ordinal logistic regression model. We demonstrated that both PPS and PBS improved the prediction of skin necrosis dramatically compared to light dose. PPS was identified as the best single parameter for predicting the PDT outcome. 相似文献
9.
Jung-Ah Kang Ji-Sun Kwak Sang-Heon Park Kyu-Young Sim Seul Ki Kim Youngnim Shin In Jung Jung Jeong-In Yang Jang-Soo Chun Sung-Gyoo Park 《Experimental & molecular medicine》2021,53(4):560
Zinc is a trace element that is essential for immune responses. Therefore, changes in cellular zinc levels in specific immune cells may influence inflammatory autoimmune diseases, such as rheumatoid arthritis (RA). However, the regulation of zinc mobilization in immune cells and its role in the pathogenesis of RA are not fully understood. Thus, we investigated the roles of zinc transporters in RA pathogenesis. We demonstrated that ZIP8 was specifically upregulated in CD4+ T cells that infiltrated the inflamed joint and that ZIP8 deficiency in CD4+ T cells abrogated collagen-induced arthritis. ZIP8 deficiency dramatically affected zinc influx in effector T cells and profoundly reduced T cell receptor (TCR)-mediated signaling, including NF-κB and MAPK signaling, which are pathways that are involved in T helper (Th) 17 cell differentiation. Taken together, our findings suggest that ZIP8 depletion in CD4+ T cells attenuates TCR signaling due to insufficient cellular zinc, thereby reducing the function of effector CD4+ T cells, including Th17 cells. Our results also suggest that targeting ZIP8 may be a useful strategy to inhibit RA development and pathogenesis.Subject terms: Autoimmunity, Immunological disorders 相似文献
10.
Jin Ho Lee Heoung Woo Kim Pyong Ki Pak Hai Bang Lee 《Journal of polymer science. Part A, Polymer chemistry》1994,32(8):1569-1579
Functional group gradient surfaces where the density of functional groups changes gradually along the sample length were prepared. The functional group (? COOH, ? CONH2, and ? OH group) gradient surfaces were produced by the treatment of low-density PE sheets using a corona with gradually increasing power, followed by the graft copolymerization of acrylic acid and subsequent substitution reaction of carboxylic acid groups to amide or hydroxyl groups. The prepared gradient surfaces were characterized by the measurement of water contact angle, FTIR-ATR, and ESCA. The gradient surfaces prepared can be used to systematically investigate the interactions of biological or other species in terms of the surface functional groups and their density of polymeric materials. © 1994 John Wiley & Sons, Inc. 相似文献