莪术醇抑制VEGF诱导的新生血管生成的实验研究

目的:研究莪术醇对血管内皮生长因子(VEGF)诱导的新生血管生成的作用及机制。方法:体外培养人脐静脉血管内皮细胞,用50ng/mL VEGF和不同浓度莪术醇进行分组处理,采用CCK-8和EdU实验检测细胞增殖,Transwell实验分析细胞迁移能力,管腔形成实验分析内皮细胞血管生成能力,Western blot检测Akt/mTORC1通路变化。结果:CCK-8实验结果显示,400、800μmol/L莪术醇+VEGF组细胞OD450值明显低于VEGF组(均P<0.01)。EdU结果显示,400μmol/L莪术醇+VEGF组细胞增殖率明显低于VEGF组(P<0.001)。Transwell实验和管腔形成实验结果显示,与VEGF组比较,400μmol/L莪术醇+VEGF组迁移细胞数减少,管腔形成的分支数量和分支长度下降(均P<0.001)。Western blot结果显示,莪术醇可显著减少细胞中Akt/mTORC1下游靶点p-Akt和p-S6的表达。结论:莪术醇可抑制VEGF诱导的血管内皮细胞的增殖、迁移和管腔形成,具有强的抑制血管生成的作用,可进一步用于眼底新生血管的治疗研究。

Synthesis of novel silica-supported chelating resin containing tert-butyl 2-picolyamino-N-acetate and its properties for selective adsorption of copper from simulated nickel electrolyte

A novel silica-supported tert-butyl 2-picolyamino-N-acetate chelating resin (Si-AMPY-1) was successfully synthesized and characterized by elemental analysis, FT-IR, SEM and 13 C CP/MAS NMR. The adsorption behaviors of the Si-AMPY-1 resin for Cu(Ⅱ) and Ni(Ⅱ) were studied with batch and column methods. The batch experiments indicated that the Si-AMPY-1 resin adsorbed Ni(Ⅱ) mainly via physisorption, while adsorbed Cu(II) via chemisorption. The column dynamic breakthrough curves revealed thatthe Si-AMPY-1 resin can efficiently separate Cu(Ⅱ) from the simulated nickel electrolyte before the breakthrough point. Moreover, the concentration of Cu(Ⅱ) in the column effluent was decreased to be less than 3 mg/L within the first 43 BV (bed volumes), and the mass ratio of Cu/Ni was 21:1 in the saturated resin, which completely satisfied the industrial requirements of the nickel electrorefining process. Therefore, it was concluded that the Si-AMPY-1 resin can be a promising candidate for the deep removal of Cu(Ⅱ) from the nickel electrolyte.

Randomized controlled study of the safety and efficacy of nitrous oxide-sedated endoscopic ultrasound-guided fine needle aspiration for digestive tract diseases

AIM To evaluate the efficacy and safety of nitrous oxidesedated endoscopic ultrasound-guided fine needle aspiration. METHODS Enrolled patients were divided randomly into an experimental group(inhalation of nitrous oxide) and a control group(inhalation of pure oxygen) and heart rate, blood oxygen saturation, blood pressure, electrocardiogram(ECG) changes, and the occurrence of complications were monitored and recorded. All patients and physicians completed satisfaction questionnaires about the examination and scored the process using a visual analog scale. RESULTS There was no significant difference in heart rate, blood oxygen saturation, blood pressure, ECG changes, or complication rate between the two groups of patients(P > 0.05). However, patient and physician satisfaction were both significantly higher in the nitrous oxide compared with the control group(P < 0.05).CONCLUSION Nitrous oxide-sedation is a safe and effective option for patients undergoing endoscopic ultrasound-guided fine needle aspiration.

Complement factor B knockdown by short hairpin RNA inhibits laser-induced choroidal neovascularization in rats

AIM:To evaluate whether recombinant complement factor B(CFB)short hairpin RNA(sh RNA)reduces laserinduced choroidal neovascularization(CNV)in rats.METHODS:Laser-induced rat CNV model was established,and then the animals underwent fundus fluorescence angiography(FFA)and hematoxylin and eosin(HE)staining.On day 3 and 7 after photocoagulation,the expression of CFB and membrane attack complex(MAC)was detected by immunhischemistry.A recombinant CFBsh RNA plasmid was constructed.CFB and scrambled sh RNA plasmids were intravenous injected into rats via the tail vein on the day of laser treatment,respectively.On day 7,the incidence of CNV was determined by FFA,and the expression of CFB and vascular endothelial growth factor(VEGF)in retinal pigment epithelium(RPE)/choroidal tissues was detected by immunhischemistry,Western blot and/or semi-quantitative reverse transcription-polymerase chain reaction(RT-PCR)in CFB and scrambled sh RNA groups.The possible adverse effects of CFB-sh RNA injection were assessed by transmission electron microscopy and electroretinography.RESULTS:FFA and HE results indicated that a laserinduced rat CNV model was successfully established on day 7 after photocoagulation.The expression of CFB and MAC was extremely weak in normal retina and choroid,and increased on day 3 after photocoagulation.However,it started to reduce on day 7.CFB sh RNA plasmid was successfully constructed and induced CFB knockdown in the retinal and choroidal tissues.FFA showed CFB knockdown significantly inhibited incidence of CNV in rats.Moreover,CFB knockdown significantly inhibited the expression of VEGF in RPE/choroidal tissues.CFB sh RNA caused no obvious side effects in eyes.CONCLUSION:CFB knockdown significantly inhibits the formation and development of CNV in vivo through reducing the expression of VEGF,which is a potential therapy target.The alternative pathway of complement activation plays an important role in CNV formation.

Infrared Photodissociation Spectroscopy of Ti＋（CO2）2Ar and Ti＋（CO2）n （n=3-7） Complexes

Ti＋（CO2）2Ar and Ti＋（CO2）n （n=3-7） complexes are produced by laser vaporization in a pulsed supersonic expansion. The ion complexes of interest are each mass-selected in a time- of-flight spectrometer, and studied with infrared photodissociation spectroscopy. For each complex, a sharp band in the CO stretching frequency region is observed, which confirms the formation of the OTi＋CO（CO2）~_l oxide-carbonyl species. Small OTi＋CO（CO2）~_1 complexes （n_〈5） exhibit CO stretching and antisymmetric CO2 stretching vibrational bands that are blue-shifted from those of free CO and CO2. The experimental observations indicate that the coordination number of CO and CO2 molecules around TiO＋ is five. Evidence is also observed for the presence of another electrostatic bonding Ti＋（CO2）2 structural isomer for the Ti＋（CO2）2Ar complex, which is characterized to have a bent OCO-Ti＋-OCO structure stabilized by argon coordination.

P-and S-wavefield simulations using both the firstand second-order separated wave equations through a high-order staggered grid finite-difference method

In seismic exploration, it is common practice to separate the P-wavefield from the S-wavefield by the elastic wavefield decomposition technique, for imaging purposes. However, it is sometimes difficult to achieve this, especially when the velocity field is complex. A useful approach in multi-component analysis and modeling is to directly solve the elastic wave equations for the pure P- or S-wavefields, referred as the separate elastic wave equa- tions. In this study, we compare two kinds of such wave equations： the first-order （velocity-stress） and the second- order （displacement-stress） separate elastic wave equa- tions, with the first-order （velocity-stress） and the second- order （displacement-stress） full （or mixed） elastic wave equations using a high-order staggered grid finite-differ- ence method. Comparisons are given of wavefield snap- shots, common-source gather seismic sections, and individual synthetic seismogram. The simulation tests show that equivalent results can be obtained, regardless of whether the first-order or second-order separate elastic wave equations are used for obtaining the pure P- or S-wavefield. The stacked pure P- and S-wavefields are equal to the mixed wave fields calculated using the corre- sponding first-order or second-order full elastic wave equations. These mixed equations are computationallyslightly less expensive than solving the separate equations. The attraction of the separate equations is that they achieve separated P- and S-wavefields which can be used to test the efficacy of wave decomposition procedures in multi-com- ponent processing. The second-order separate elastic wave equations are a good choice because they offer information on the pure P-wave or S-wave displacements.

Solid Solute Regularity of La Atom inα-Fe Supercell by First-principles

The structure stability, elastic property and electronic structure of a-Fe supercell with La atom were inves- tigated by first-principles, in which, generalized gradient approximation （GGA） with the Perdew Burke Ernzerhof （PBE） was used as exchange-correlation functional, a-Fe supercells with La atom include a-Fe supercell with La atom in octahedral interstitial solid solute （La-OISS）, that with La atom in tetrahedral interstitial solid solute （La-TISS） and that with La atom in substitutional solid solute （La-SSS）. The results show that the La-SSS a-Fe supercell is more stable than La-OISS one. The resistance to volume change, reversible deformation and stiffness of La-OISS a-Fe supercell are stronger than those of La-SSS one. Moreover, the degrees of anisotropy and ionization in La-SSS a-Fe supercell are both stronger than those in La-OISS one. The bonding strength between La atom and Fe atom in La-SSS a-Fe supercell is larger than that in La-OISS one.