Fractures in oil and gas reservoirs have been the topic of many studies and have attracted reservoir research all over the world. Because of the complexities of the fractures, it is difficult to use ...fractured reservoir core samples to investigate true underground conditions. Due to the diversity of the fracture parameters, the simulation and evaluation of fractured rock in the laboratory setting is also difficult. Previous researchers have typically used a single material, such as resin, to simulate fractures. There has been a great deal of simplifying of the materials and conditions, which has led to disappointing results in application. In the present study, sandstone core samples were selected and sectioned to simulate fractures, and the changes of the compressional and shear waves were measured with the gradual increasing of the fracture width. The effects of the simulated fracture width on the acoustic wave velocity and amplitude were analyzed. Two variables were defined： H represents the amplitude attenuation ratio of the compressional and shear wave, and x represents the transit time difference value of the shear wave and compressional wave divided by the transit time of the compressional wave. The effect of fracture width on these two physical quantities was then analyzed. Finally, the methods of quantitative evaluation for fracture width with H and x were obtained. The experimental results showed that the rock fractures linearly reduced the velocity of the shear and compressional waves. The effect of twin fractures on thecompressional velocity was almost equal to that of a single fracture which had the same fracture width as the sum of the twin fractures. At the same time, the existence of fractures led to acoustic wave amplitude attenuations, and the compressional wave attenuation was two times greater than that of the shear wave. In this paper, a method was proposed to calculate the fracture width with x and H, then this was applied to the array acoustic imaging logging data.The application examples showed that the calculated fracture width could be compared with fractures on the electric imaging logs. These rules were applied in the well logs to effectively evaluate the fractures, under the case of no image logs, which had significance to prospecting and development of oil and gas in fractured reservoirs.
In this study, we isolated a virus strain （YN12031） from specimens of Armigeres subalbatus collected in the China-Laos border. BHK-21 cells infected with YN12031 exhibited an evident cytopathic ...effect （CPE） 32 h post-infection. The virus particles were spherical, 70 nm in diameter, and enveloped; they also featured surface fibers.
Ca-α/β-SiAlON composites were prepared using Ca-α/β-SiAlON powder synthesized from gold ore tailings, which contained abundant Si and Al elements as the major raw materials together with minor ...additives, through a pressure-less sintering method. The influ- ences of sintering temperature on the phase composition and mierostrueture of the composites were analyzed. The scanning electron micros- copy images of the composites show the interlacing of grains with elongated columnar, short columnar and plate-like morphologies. The composites sintered at 1520℃ for 6 h have a flexural strength of 352 MPa, Vickers hardness of 11.2 GPa, and fracture toughness of 4.8 MPa·m1/2. The relative content of each phase in the products is I（Ca-α-SiAION）：I（β-SiAlON）：I（Fe3Si） = 23：74：3, where Ii stands for the dif- fraction peak intensity of phase i.
To compare the efficacy of various irrigants (citric acid, ethylenediaminetetraacetic acid (EDTA) and NaOCl) and techniques in removing Ca(OH)2 in two types of curved root canal systems, simulated ...root canals with specific curvatures were used to investigate the effects of different irrigants and instruments on Ca(OH)2 removal. The optimal methods were verified on extracted human teeth. Simulated root canals were assigned to one of two groups based on the irrigation solution:10% citric acid or 2.5%NaOCl. Each group was divided into four subgroups according to the technique used to remove Ca(OH)2. The percentage of Ca(OH)2 removal in different sections of root canals was calculated. On the basis of the results obtained for the simulated canals, 10%citric acid and 17% EDTA were applied to remove Ca(OH)2 from the extracted human teeth with curved root canal systems. The teeth were scanned by micro computed tomography to calculate the percentage of Ca(OH)2 removal in the canals. In simulated root canals, we found that 10% citric acid removed more Ca(OH)2 than 2.5% NaOCl in the 0–1 mm group from the apex level (P<0.05). Ultrasonic and EndoActivator activation significantly removed more Ca(OH)2 than a size 30 K file in the apical third (P<0.05). However, there were no significant differences in any sections of the canals for 10%citric acid or 17%EDTA in removing Ca(OH)2 in extracted human teeth. We concluded that it was effective to remove residual Ca(OH)2 using the decalcifying solution with EndoActivator or Passive Ultrasonic Irrigation in a curved root canal system. A protocol for Ca(OH)2 removal was provided based on the conclusions of this study and the methods recommended in previous studies.
To compare the efficacy of various irrigants （citric acid, ethylenediaminetetraacetic acid （EDTA） and NaOCI） and techniques inremoving Ca（OH）2 in two types of curved root canal systems, simulated ...root canals with specific curvatures were used toinvestigate the effects of different irrigants and instruments on Ca（OH）2 removal, The optimal methods were verified on extractedhuman teeth. Simulated root canals were assigned to one of two groups based on the irrigation solution： 10% citric acid or2,5% NaOCI, Each group was divided into four subgroups according to the technique used to remove Ca（OH）2. The percentageof Ca（OH）2 removal in different sections of root canals was calculated. On the basis of the results obtained for the simulatedcanals, 10% citric acid and 17% EDTA were applied to remove Ca（OH）2 from the extracted human teeth with curved root canalsystems. The teeth were scanned by micro computed tomography to calculate the percentage of Ca（OH）2 removal in the canals.In simulated root canals, we found that 10% citric acid removed more Ca（OH）2 than 2.5% NaOCI in the 0-1 mm group from theapex level （P〈O.05）. Ultrasonic and EndoActivator activation significantly removed more Ca（OH）2 than a size 30 K file in theapical third （P〈 0.05）. However, there were no significant differences in any sections of the canals for 10% citric acid or 17%EDTA in removing Ca（OH）2 in extracted human teeth. We concluded that it was effective to remove residual Ca（OH）2 using thedecalcifying solution with EndoActivator or Passive Ultrasonic Irrigation in a curved root canal system. A protocol for Ca（OH）2removal was provided based on the conclusions of this study and the methods recommended in previous studies.
Aim： The non-neuronal acetylcholine system （NNAS） in endothelial cells participates in modulating endothelial function, vascular tone, angiogenesis and inflammation, thus plays a critical role in ...cardiovascular diseases. In this study, we used a proteomic approach to study potential downstream receptor-effectors of NNAS that were involved in regulating cellular function in endothelial cells. Methods： Human umbilical vein endothelial cells were incubated in the presence of acetylcholine, oxotremorine, pilocarpine or nicotine at the concentration of 10 pmol/L for 12 h, and the expressed proteins in the cells were separated and identified with two-dimensional electrophoresis （2-DE） and LC-MS. The protein spots with the largest changes were identified by LC-MS. Biowork software was used for database search of the peptide mass fingerprints. Results： Over 1200 polypeptides were reproducibly detected in 2-DE with a pH range of 3-10. Acetylcholine, oxotremorine, pilocarpine and nicotine treatment caused 16, 9, 8 and 9 protein spots, respectively, expressed differentially. Four protein spots were identified as destrin, FK506 binding protein 1A （FKBPIA）, macrophage migration inhibitory factor （MIF） and profilin-l. Western blotting analyses showed that treatment of the cells with cholinergic agonists significantly decreased the expression of destrin, FKBPIA and MIF, and increased the expression of profilin-l. Conclusion： A set of proteins differentially expressed in endothelial cells in response to cholinergic agonists may have important implications for the downstream biological effects of NNAS.
The high efficient blowing technique includes increasing oxygen supply intensity and optimizing slag forming. The oxygen supply intensity on 300 t converters of No. 1 steelmaking shop at Baosteel ...reaches 3.83 m^3/（t · min）, and at Taiyuan Steel, Lianyuan Steel, Pingxiang Steel and other steel plants, the oxygen supply intensity on medium converters is in the range of 4.0--4.4m^3/（t · min）. The productivity of converter can be increased by 8% -- 15% with adopting this technique. The whole technique, including design and manufacture of lance nozzle with reasonable pacnolontenue of outlets, technique of oxygen supply and slag forming, has been developed by CISRI to meet the need of technique transfer.
Mercury is usually added to skin-lightening products due to its whitening effect.The Food and Drug Administration （FDA） limits the amount of mercury in cosmetics to trace amounts under 1 ...ppm.Nevertheless,many cosmetics contain mercury above 1000 ppm to increase the whitening effect.In a group of special patients in the study,pain,renal damage,and neuropsychiatric symptoms were the cardinal symptoms observed.
Background The conventional thoracic endovascular aortic repair （TEVAR） involves groin incisions under general or epidural anesthesia. As technology moves towards less invasive procedures, a total ...percutaneous approach is desirable.In this study, we describe a Preclosing technique and investigate its safety and efficacy for femoral access sites management, and evaluate its advantages as compared to those of traditional surgical cutdown approaches.Methods The Preclosing technique involves two or multiple 6 F Perclose Proglide devices deployed in the femoral artery before upsizing to a 20-25 F sheath. The sutures were secured to close the arteriotomy at the end of the procedure. The medical records of patients who underwent thoracic endovascular aortic repairs using the Preclosing technique between December 2009 and November 2010 （group A） were compared with those using surgical femoral cutdown from January 2008 to November 2009 （group B）. Outcome measures included rates of technical success, early complications, anesthesia method, procedure time, cardiac care unit （CCU） stay, time from procedure to discharge,hospital stay, procedure expense, hospital cost.Results Between the two groups, there were no significant differences in baseline characteristics, in the endograft models or profiles. The technical success rate was 100.0% （85/85） in group A vs. 97.4% （147/151） in group B （P 〈0.05）.There was no access-related mortality in both groups. Compared with group B, the incidence of early complications were fewer in group A, 9.4% （8/85） vs. 22.5% （34/151） （P 〈0.01）. Local anesthesia with conscious sedation was used more often in group A, 68.2% （58/85） vs. 51.7% （78/151） in group B （P〈0.01）. The procedure duration was shorter, （96±33）minutes in group Avs. （127±41） minutes in group B （P〈0.01）. The length of the CCU stay, the duration from procedure to discharge, and the hospital stay were both reduced in group A, （117.3±88.3） hours, （7.5±5.3） days and （15.3±6.8） days vs. （132.7±115.5） hours, （10.5±5.0） days and （19.5±7.8） days in group B （P〈0.01）. The procedure cost was RMB （109 000±30 000） Yuan in group A vs. RMB （108 000±25 000） Yuan in group B （P=NS）. The hospital cost was RMB （130 000±35 000） Yuan in group A vs. RMB （128 000±33 000） Yuan in group B （P=NS）.Conclusions Total percutaneous TEAVR with the Preclosing technique is safe and effective with meticulous technique and appropriate patient selection. The Preclosing technique decreases access-related complications, depends less on general anesthesia and the surgeon＇s cooperation, saves procedure time and shortens the CCU/hospital stay. With these advantages, the use of two percutaneous closure devices increases the hospital cost only slightly.
AIM： To evaluate the growth inhibition efficacy of atofluding derivative N3-o-toluyl-fluorouracil （TFU） on human gastric carcinoma cell lines SGC-7901 and MKN-45. METHODS： Cell growth inhibition by ...TFU was measured by MTT and clonogenic assays without or with liver microsomal enzymes. Xenografts of cancer cells in nude mice were employed to study the anti-proliferative effects of TFU in vivo. RESULTS： TFU inhibited the growth of SGC-7901 and MKN-45 cells. However, the inhibitory effects of TFU on cell growth were not significant. The inhibition rates were enhanced in the presence of liver microsomal enzymes, ranging 4.73%-48.57% in SGC-7901 cells and 9.0%-62.02% in MKN-45 cells. In v/vo, TFU delayed the growth of SGC-7901 and MKN-45 cells in nude mice. The inhibition rates were 40.49%, 63.24%, and 75.98% in SGC-7901 cells and 40.76%, 61.41%, and 82.07% in MKN-45 cells when the oral doses were 25, 50, and 100 mg/kg, respectively. TFU treatment was generally well tolerated by mice with less than 20% reduction in body weight. CONCLUSION： TFU inhibits the growth of human gastric carcinoma cells. The inhibition rates are increased in the presence of liver microsomal enzymes. The efficacy of TFU may be associated with the sustaining release of 5-fluorouracil （5-FU） mediated by the enzymes.
PDF
