排序方式: 共有26条查询结果,搜索用时 15 毫秒
1.
A new series of DNA binding 5,10,15-tri(N-methyl-4-pyridiniumyl)porphyrin (TrisMPyP)-platinum(II) conjugates was synthesized, in which different spacer ligands were used for appropriate coordination to platinum(II) complexes. Compound 9b exhibited in vivo antitumor activity (T/C%, 294) superior to cisplatin (T/C%, 184) against the leukemia L1210 cell line. 相似文献
2.
Kyungsik Ock Gabsoo Jang Yongrae Roh Sunghoon Kim Jaeho Kim Kwangnak Koh 《Microchemical Journal》2001,70(3)
In this study, we have fabricated Cu2+ ion sensor using a squarylium dye (SQ-dye) containing polymeric thin-film. Surface Plasmon Resonance (SPR) was used as a signal amplifier to achieve high sensitivity and large linear dynamic range for detection of Cu2+ ion. High selectivity to Cu2+ ion was obtained by the effective electro-static interaction between SQ-dye and Cu2+ ion in the polymeric film. The optimal analytical condition of high selectivity and sensitivity in the wider linear dynamic range obtained in this study may be a result of the cooperative ‘hard-soft’ metal ion-ligand interaction and effective detection of refractive index changes by the complexation of Cu2+ ion and SQ-dye in SPR measurement. Among 10 different alkali metal, alkaline earth metal, and transition metal ions, SQ-dye in poly(vinylchloride)–poly(vinyl acetate)–poly(vinyl alcohol) (PVC–PVAc–PVA) copolymer film showed the highest selectivity to Cu2+ ion. Although the interaction between SQ-dye and metal ions has not been well understood, both cooperative ‘hard-soft’ metal ion-ligand interaction and size-selective recognition of Cu2+ ion to SQ-dye may contribute to high selectivity. Furthermore, additional sensitivity in the detection of Cu2+ ion by SPR was obtained by matching the wavelength of probing radiation of SPR and absorption maximum of SQ-dye at 675 nm, which allow to detect small changes in the refractive index by complex formation on the sensing surface. This result may apply in development of the Cu2+ ion selective sensor for medical, biochemical, and environmental applications. 相似文献
3.
We discuss the notion of spin squeezing considering two mutually exclusive classes of spin-s states, namely, oriented and non-oriented states. Our analysis shows that the oriented states are not squeezed while non-oriented
states exhibit squeezing. We also present a new scheme for construction of spin-s states using 2s spinors oriented along different axes. Taking the case of s=1, we show that the ‘non-oriented’ nature and hence squeezing arise from the intrinsic quantum correlations that exist among
the spinors in the coupled state. 相似文献
4.
Jung Ji-Young Kay Chul Seung Son Seok Hyun Shin Hun-Joo Kim Myong Ho Choi Byung Ock Kang Young-nam Seo Jae-Hyuk Lee Gi Woong Park Hyong Wook 《Journal of the Korean Physical Society》2012,60(1):137-141
Journal of the Korean Physical Society - Tomotherapy (TomoTherapy, Inc., Madison, WI, USA) is a helical intensity modulated radiation therapy (IMRT) modality using rotational delivery of a fan beam... 相似文献
5.
The aim of this brief report is to study the behaviour of sheath structure in a multi-component plasma with dust-neutral collisions.
The plasma consists of electrons, ions, micron size negatively charged dust particles and neutrals. The sheath-edge potential
and sheath width are calculated for collisionally dominated sheath. Comparison of collisionless and collisionally dominated
sheath are made. 相似文献
6.
We report a practical world-to-chip microfluidic interfacing method with built-in valves suitable for microscale multichamber chip-based assays. One of the primary challenges associated with the successful commercialization of fully integrated microfluidic systems has been the lack of reliable world-to-chip microfluidic interconnections. After sample loading and sealing, leakage tests were conducted at 100 degrees C for 30 min and no detectable leakage flows were found during the test for 100 microchambers. To demonstrate the utility of our world-to-chip microfluidic interface, we designed a microscale PCR chip with four chambers and performed PCR assays. The PCR results yielded a 100% success rate with no contamination or leakage failures. In conclusion, we have introduced a simple and inexpensive microfluidic interfacing system for both sample loading and sealing with no dead volume, no leakage flow and biochemical compatibility. 相似文献
7.
High-efficiency condenser-type diffusion denuders of cylindrical and planar geometries are described. The film condensation of water vapor onto a cooled denuder surface can be used as a method for collecting water-soluble gases. By using SO(2) as the test gas, the planar design offers quantitative collection efficiency at air sampling rates up to 5 L min(-1). Coupled to ion chromatography, the limit of detection (LOD) for SO(2) is 0.014 ppbv with a 30-min successive analysis sequence. The method has been successfully applied to the analysis of temperature- and humidity-controlled cleanroom air. 相似文献
8.
Despite gaps in our knowledge of how phytochemicals interfere with cellular functions, several natural plant products are utilized to prevent or treat a wide range of diseases. Identification of an agent with therapeutic potential requires multiple steps involving in vitro studies, efficacy and toxicity studies in animal models, and then human clinical trials. This review provides a brief introduction on natural products that may help to treat and/or prevent bronchial asthma and describes our current understanding of their molecular mechanisms based on various in vitro, in vivo, and clinical studies. We focus on the anti-inflammatory and anti-vascular actions of the plant products and other roles beyond the anti-oxidative effects. 相似文献
9.
A continuous time risk process is considered, where the premium rate is constant and the claims form a compound Poisson process. We assume that an action is taken, either an investment to other business when the level of surplus reaches V>0 or an injection of capital when the surplus goes below τ(0<τ<V). After assigning several costs related to managing the surplus, we obtain the long-run average cost per unit time. A numerical example is studied. 相似文献
10.
The multiresidue method used in this study allows the determination of 101 pesticides, including organophosphorus, organochlorine, and nitrogen-containing pesticides, in crops by gas chromatography with mass selective detector. Analysis was performed in the selected-ion monitoring mode, and the identities of the positive analytes were confirmed by retention time and the ratios of selected ions. The selected ion mode demonstrated an acceptable selectivity for most of the pesticides determined in 3 kinds of samples (Chrysanthemum coronarium; Perilla japonica, leaf; and Lactuca savita, which are very popular vegetables eaten raw in Korea), and very minor interferences were observed in the elution area of the pesticide analytes. Samples were spiked with pesticides at 0.1-1.0 mg/kg. The recoveries of 90% of the pesticides were between 70 and 110%; however, the recoveries of acephate and folpet were very poor, i.e., < 50%. The limits of detection (LODs) for most pesticides were between 0.02 and 0.3 mg/kg, and the LODs for about half of the pesticeds studied were < 0.05 mg/kg. 相似文献