DNA Modification with Photochromic Spiro Compounds

The photochromic spiropyrans and spirooxazine having a succinimidyl ester or isothiocyanate pendant group can form covalent products with transaminated DNA. The absorption spectra and solid reflection spectra of modified DNA with these photochromic spiro compounds were investigated.

Influence of Rolling Treatment on Interfacial Shear Strength of Steel-mushy Al-7graphite Bonding Plate

At room temperature, the rolling treatment of steel-mushy Al-7graphite bonding plate was carried out under different relative reduction. The influence of rolling on interfacial mechanical property of this bonding plate was studied. The results show that, for steel-mushy Al-7graphite bonding plate which is made up of 1.2 mm in thickness 08AI steel plate and 2.0 mm in thickness Al-7graphite layer, there is a nonlinear relationship between interfacial shear strength of bonding plate and relative reduction of rolling. When relative reduction of rolling is smaller than 2.59%, with the increasing of relative reduction, interfacial shear strength of bonding plate increases gradually. When relative reduction of rolling is bigger than 2.59%, with the increasing of relative reduction, interfacial shear strength of bonding plate decreases continuously. When relative reduction of rolling is 2.59%, the largest interfacial shear strength 77.0 MPa can be obtained.

Influence of diffusion time on property of steel-aluminum solid to liquid bonding

The bonding of solid steel to liquid aluminum was conducted using rapidsolidification. The influence of diffusion time on interfacial shear strength was studied. Theresults show that when the temperature of aluminum liquid is 700℃ and the preheat temperature ofsteel plate is 250℃, the relationship between diffusion time (t) and interfacial shear strength(σ) is σ =15.1+8.14t-037t^2 +0.005t^3, and the maximum interfacial shear strength is 71.1 MPa.

c-src activating mutation analysis in Chinese patients with colorectal cancer

AIM: To investigate the occurrence of cellular src (c-src)activating mutation at codon 531 in colorectal cancer patients from Chinese mainland.METHODS: Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay followed by sequencing and single-strand conformation polymorphism analysis were carried out to screen 110 samples of primary colorectal cancer and 20 colorectal liver metastases.RESULTS: Only one sample showed PCR-RFLP-positive results and carried somatic codon 531 mutations. No additional mutation of c-src exon 12 was found.CONCLUSION: c-src codon 531 mutation in colorectal cancer is not the cause of c-src activation.

Structure-activity relationships for anti-inflammatory effect of flavonoids

OBJECTIVE The present study examined the potential of flavonoids in reducing airway inflammation and determined the structure activity relationships(SAR),if present,for their anti-inflammatory effects.METHODS Seventeen flavonoids with different chemical structures were selected for the study.Inflammation was induced in human bronchial epithelial BEAS-2B cells with lipopolysaccharide(LPS).BEAS-2Bcells were incubated with or without different flavonoids(10μmol·L-1)1hbefore treatment with LPS(10μg·mL-1)for 24 h.The viability of the cells after exposure to LPS and/or flavonoids were determined by thiazolyl blue tetrazolium bromide(MTT)assay.The amount of the inflammatory mediators,interleukin(IL)-6,IL-8 and monocyte chemoattractant protein-1(MCP-1),were measured in the supernatants byenzyme-linked immunosorbent assay(ELISA).RESULTS Flavonoids(1to 10μmol·L-1)and LPS(1 to 10μg·mL-1)did not affect the viability of BEAS-2B cells.LPS(10μg·mL-1)significantly stimulated the release of IL-6,IL-8 and MCP-1 in BEAS-2B cells.Among the flavonoids tested,only apigenin,luteolin and genistein(10μmol·L-1)significantly inhibited the release of the inflammatory mediators.CONCLUSION These findings suggested that a hydroxy group at C5 and C7 positions in the A ring,a double bond between C2 and C3 and acarbonyl group at the C4 position in the C ring of the flavonoid might play an important role for their anti-inflammatory effect.The presence of a hydroxy group at C3 position or glycosylation at C3 or C7 position reduces the effectiveness of a flavonoid as an anti-inflammatory agent.

Influence of Solid Fraction on Structure of QTi3.5-15/Graghite Slurry

The electromagnetic-mechanical stirring technology was used to prepare QTi3.5-15/graghite slurry. The distribution of graphite particies in QTi3.5-15/graghite slurry was studied using cold quenching method. The results show that solid fraction of QTi3.5-15/graphite slurry increases with the decreasing of stirring temperature. There is a linear relationship between solid fraction and stirring temperature. With the increasing of solid fraction, the distribution of graphite particies in slurry becomes uniform gradually. When the solid fraction is larger than 45%, the rising of graphite particies in slurry can be restricted, and QTi3.5-15/graghite slurry with uniform distribution of graphite particies can be prepared.

Study on Mechanical Property in Steel-Aluminum Solid to Liquid Bonding

The bonding of solid steel plate to liquid Al was conducted using rapid solidification. The influence of thickness of Fe-Al compound layer at the interface on interfacial shear strength of bonding plate was studied. The results show that the relationship between thickness of Fe-AI compound layer and interfacial shear strength is 5=30.4+8.51 h-0.51 h2 +0.007 h3 (where h is thickness of Fe-AI compound layer, S is interfacial shear strength). When thickness of Fe-AI compound layer is 10.7 um, the largest interfacial shear strength is 71.6 MPa.

A Novel Method for Quantification of Circulating DNA in Serum by Capillary Zone Electrophoresis

In this paper, we first presented a novel method for quantification of circulating DNA in human serum based on capillary zone electrophoresis with laser-induced fluorescence detection (CZE-LIF). The serum was digested by proteinase to release free DNA, and then CZE-LIF system was used for the quantification of total circulating DNA. This method was successfully used to quantify the circulating DNA levels in sera from healthy individuals and certain cancer patients. We found the significantly elevated circulating DNA levels in certain prostate cancer patients. Our results demonstrated that CZE-LIF system has good linearity, excellent sensitivity (0.5 ng/mL DNA), satisfactory reproducibility (RSDs in one day and between days were both less than 5%) and reliability, and is well suitable to the quantification of the circulating DNA in human serum or plasma.

Interfacial Structure of Steel-Mushy Al-20Sn Bonding Plate

Fe-AI compound at the interface of steel-mushy AI-20Sn bonding plate was studied quantitatively. The relationship between ratio of Fe-AI compound at interface and bonding parameters (such as preheat temperature of steel plate, solid fraction of AI-20Sn slurry and rolling speed) was established by artificial neural networks perfectly. The results show that when the bonding parameters are 505℃ for preheat temperature of steel plate, 34.3% for solid fraction of AI-20Sn slurry and 10 mm/s for rolling speed, the reasonable ratio of Fe-AI compound corresponding to the largest interfacial shear strength of bonding plate is obtained. Its value is 72%. This reasonable ratio of Fe-AI compound is a quantitative criterion of interfacial embrittlement, that is, when the ratio of Fe-AI compound at interface is larger than 72%, interfacial embrittlement will occur.

Influence of Diffusion Time on Steel-Aluminum Solid to Liquid Bonding Interfacial Structure

The bonding of steel plate to aluminum liquid was conducted using rapid solidification. The influence of diffusion time on interfacial structure was studied. The results showed that under the condition of 750癈 for the temperature of aluminum liquid and 200癈 for the preheat temperature of steel plate, when diffusion time was shorter than 4.3 s, there was only Fe-AI solid solution at the interface. When diffusion time was longer than 4.3 s, Fe-AI compound began to form at the interface. The relationships between diffusion time t and thickness of Fe-AI compound layer H are H=-9.72+2.62t-0.08t2 (4.3 s<t<15 s) and H=2.79+0.647t-0.033t2 (t>15 s).

Thickness of compound layer in steel-aluminum solid to liquid bonding

The bonding of solid steel plate to liquid aluminum was studied using rapidsolidification. The surface of solid steel plate was defatted, descaled, immersed (in K_2ZrF_6 fluxaqueous solution) and stoved. In order to determine the thickness of Fe-Al compound layer at theinterface of steel-aluminum solid to liquid bonding under rapid solidification, the interface ofbonding plate was investigated by SEM (Scanning Electron Microscope) experiment. The relationshipbetween bonding parameters (such as preheat temperature of steel plate, temperature of aluminumliquid and bonding time) and thickness of Fe-Al compound layer at the interface was established byartificial neural networks (ANN) perfectly. The maximum of relative error between the output and thedesired output of the ANN is only 5.4%. From the bonding parameters for the largest interfacialshear strength of bonding plate (226℃ for preheat temperature of steel plate, 723℃ for temperatureof aluminum liquid and 15.8 s for bonding time), the reasonable thickness of Fe-Al compound layer10.8 μm was got.

Interfacial mechanical property of steel-mushy Al-20Sn bonding

The bonding of a steel plate to Al-20Sn slurry was conducted using thecasting rolling technique. The surface of the steel plate was defatted, descaled, immersed (inK_2ZrF_6 flux aqueous solution) and stoved. Al-20Sn slurry was prepared using the electromagneticmechanical starring method. The interfacial mechanical property of the bonding plate was researchedto determine the relationship between the diffusion time and the interfacial shear strength. Inorder to identify the mechanism of bonding, the interfacial structure of the bonding plate wasstudied. The results show that at a prebeat temperature of the steel plate of 505 deg C and a solidfraction of Al-20Sn slurry of 35 percent, the relationship between the interfacial shear strength Sand the diffusion time t is S=28.8+4.3t-0.134t^2 +0.0011t^3. When the diffusion time is 22 s, thelargest interfacial shear strength is 70.3 MPa, and the corresponding interface is a new one whichis made up of Fe-Al compound and Fe-Al solid solution alternatively and in a right proportion. Inthis interfacial structure, the interfacial embrittlement does not happen and Fe-Al compound canplay its role in strong combination adequately.

LaNiO3 modified with Ag nanoparticles as an efficient bifunctional electrocatalyst for rechargeable zinc-air batteries

No-precious bifunctional catalysts with high electrochemical activities and stability were crucial to properties of rechargeable zinc-air batteries.Herein,LaNiO3 modified with Ag nanoparticles(Ag/LaNiO3)was prepared by the co-synthesis method and evaluated as the bifunctional oxygen catalyst for oxygen reduction reaction(ORR)and oxygen evolution reaction(OER).Compared with LaNiO3,Ag/LaNiO3 demonstrated the enhanced catalytic activity towards ORR/OER as well as higher limited current density and lower onset potential.Moreover,the potential gap between ORR potential(at-3 mA cm^-2)and OER potential(at 5 mA cm^-2)was 1.16 V.The maximum power density of the primary zinc-air battery with Ag/LaNiO3 catalyst achieved 60 mW cm^-2.Furthermore,rechargeable zinc-air batteries operated reversible charge-discharge cycles for 150 cycles without noticeable performance deterioration,which showed its excellent bifunctional activity and cycling stability as oxygen electrocatalyst for rechargeable zinc-air batteries.These results indicated that Ag/LaNiO3 prepared by the co-synthesis method was a promising bifunctional catalyst for rechargeable zinc-air batteries.