A prospective randomized trial of transnasal ileus tube vs nasogastric tube for adhesive small bowel obstruction

AIM:To study the therapeutic efficacy of a new transnasal ileus tube advanced endoscopically for adhesive small bowel obstruction.METHODS:A total of 186 patients with adhesive small bowel obstruction treated from September 2007 to February 2011 were enrolled into this prospective randomized controlled study.The endoscopically advanced new ileus tube was used for gastrointestinal decompression in 96 patients and ordinary nasogastric tube(NGT) was used in 90 patients.The therapeutic efficacy was compared between the two groups.RESULTS:Compared with the NGT group,the ileus tube group experienced significantly shorter time for relief of clinical symptoms and improvement in the findings of abdominal radiograph(4.1 ± 2.3 d vs 8.5 ± 5.0 d) and laboratory tests(P < 0.01).The overall effectiveness rate was up to 89.6% in the ileus tube group and 46.7% in the NGT group(P < 0.01).And 10.4% of the patients in the ileus tube group and 53.3% of the NGT group underwent surgery.For recurrent adhesive bowel obstruction,ileus tube was also significantly more effective than NGT(95.8% vs 31.6%).In the ileus tube group,the drainage output on the first day and the length of hospital stay were significantly different depending on the treatment success or failure(P < 0.05).The abdominal radiographic improvement was correlated with whether or not the patient underwent surgery.CONCLUSION:Ileus tube can be used for adhesive small bowel obstruction.Endoscopic placement of the ileus tube is convenient and worthy to be promoted despite the potential risks.

Optimum Level of Replacement Slag in OPC-Slag Mortars

The present paper reports the testing of 14 OPC-slag mortars and 2 controls OPC and slag mortars. The main aim is to determine the optimum level of replacement slag for achievement to the highest early strength with reasonable flow. Variable was the level of GGBFS in the binder. In this experimental work, two types of sands were used that are： silica and mining sands. It is determined that the optimum level of replacement slag is 40% and use of silica sand in OPC is preferable to mining sand and reversely, use of mining sand is preferred in GG100 to silica sand. All mortars had W/B and S/B 0.33 and 2.25, respectively.

LZK流量自动控制装置的理论与实践

LZK流量自动控制装置是将流量计与定量控制阀设计为一体的新型流量自动控制装置。该装置能够在很宽的流量范围内自动进行精确测量,同时具有现场控制和远传显示等多种功能,容易操作,显示直观,维修方便,广泛使用于各种液体的定量控制。欢采现场应用见到了明显的效果,还极大地减轻了工人的劳动强度。

Constitutive Model of Saturated Soft Clay with Cyclic Loads under Unconsolidated Undrained Condition

An equivalent visco-elastic model of saturated soft clay was studied under unconsolidated undrained (UU) condition, which can be used to evaluate the stability of ocean foundation. Cyclic triaxial compression and extension tests were conducted to study the parameters of the model. Results showed that the relationships of the damping ratio and the octahedral shear modulus with the octahedral cyclic shear strain were nearly unique, when the initial octahedral shear stress ratios of specimens were equal to 0.3, 0.5 and 0.7. The relationships of the damping ratio and the octahedral shear modulus with the octahedral cyclic shear strain determined from the cyclic triaxial compression tests were basically the same as those determined from the cyclic triaxial extension tests. Furthermore, the relationships were not related to the initial stress condition, the test stress state and the octahedral cyclic shear stress ratio. The relationships determined from the cyclic triaxial tests under no deviatoric stress were basically the same as those determined from the cyclic triaxial tests under deviatoric stress. The change of the octahedral cyclic accumulative strain with the number of cycles was unique under different tests stress states. An equivalent visco-elastic constitutive model of saturated soft clay under UU condition was initially established.

EXPRESSION OF INTERCELLULAR ADHESION MOLECULE IN LUNG TISSUES OF EXPERIMENTAL ACUTE LUNG INJURY AND THE AFFECT OF RHUBARB ON IT

Objective. To approach the relation and the possible mechanism between the expression of intercellular adhesion molecule (ICAM1) mRNA and acute lung injury (ALI) and the mechanisms of rhubarb in the prevention and treatment of the lung injury. Methods. Lipopolysaccharide (LPS) was injected into the sublingual vein of male Wistar rats to perform ALI animal model. The rats were divided into 4 groups: LPS group, control group, rhubarb group and dexamethasone group. Macroscopic and histopathological examinations were performed and biological markers were measured for the lung specimens. The markers included lung wet/dry weight, the rate of neutrophils and protein content in the pulmonary alveolar lavage fluid, pulmonary vascular permeability and pulmonary alveolar permeability index. Molecular hybridization method was used to determine the expression of ICAM1 mRNA. Results. In the lung tissues, the ICAM1 mRNA expression was increased in the endothelial cells of pulmonary veins and capillaries, rhubarb and dexamethasone had the action of decreasing the expression. The light reflex value in the gray scale scanning showed that in the comparison between the LPS and the control group, the gray scale value of the lung tissues in ALI was significantly increased, thus the light reflex value was markedly decreased (P<001), demonstrating the expression of ICAM1 mRNA was increased. In comparison with the LPS group, dexamethasone and rhubarb could decrease the gray scale value of the lung tissue significantly, thus the light reflex value was elevated (P<001, P<005); the corresponding pathologic changes of lung tissues and the biological markers of the lung injury were significantly decreased or ameliorated. Conclusions. The increase of the expression of ICAM1 mRNA in the lung tissues of ALI plays the roles in ALI. The application of rhubarb and dexamethasone can decrease the expression and ameliorate the lung damage; its mechanism is possibly via the inhibition of ICAM1 mRNA expression.

Experimental investigation and development of new correlation for influences of temperature and concentration on dynamic viscosity of MWCNT-SiO2(20-80)/20W50 hybrid nano-lubricant

In current research, MWCNT-SiO2/oil hybrid nano-lubricant viscosity is experimentally examined. By dispersing 0.05%, 0.1%, 0.2%, 0.4%, 0.8% and 1% volume of MWCNTs and SiO2 nanopartide into the engine oil SAE 20W50, the temperature and solid volume fraction consequences were studied. At 40 to 100 ℃ temperature, the viscosities were assessed. The results indicated Newtonian behavior for the hybrid nano-lubricant. Moreover, solid volume fraction augmentation and temperature enhanced the viscosity enhancement of hybrid nano-lubricant. At highest solid volume fraction and temperature, nano-lubricant viscosity was 171% greater compared to pure 20W50. Existed models lack the ability to predict the hybrid nano-lubricant viscosity. Thus, a new correlation regarding solid volume fraction and temperature was suggested with R-squared of 0.9943.

Rolling thin film oven test investigation for polymer modified asphalt

Rolling Thin Film Oven Test （RTFOT） is the AASHTO T240 standard method to simulate asphalt plant mix aging. But it has proven inadequate in aging polymer-modified asphalts （PMA）. NCHRP 9-10 offered a modified RTFOT （MRTFOT） by adding a steel rod in each bottle. Since construction temperature of PMA mixture is 10 ℃ -20 ℃ higher than that of conventional asphalt mixtures in the field, elevating RTFOT temperature for PMA is necessary for adequate aging and proper simulation. Six PMAs with various PG grades and sources were aged with RTFO at elevated temperatures. Some were also treated with MRTFOT for comparison. SHRP performance grade and phase angle were used as indicators to analyze the effects of RTFOT under different conditions. The results show that elevating the temperature is more effective than using rods. And PMA RTFOT temperature could be determined by equiviscous principle. From limited data, O. 25 Pa ~ s is tentatively proposed as critical viscosity for PMA, but still more work is necessary to validate this. Given the fact that equiviscous principle is seldom used in field practice, a simple approach was proposed： 173 ℃ is used for RTFOT of PG70 PMAs （grading herein from un-aged asphalts） , while 178 ℃ is for PMAs of PG76 or PG82 and 20 ℃ higher than standard 163 ℃ is necessary for PG 88 or stiffer PMAs.

Bonding Characteristics and Flexural Stiffening Effect of Carbon Fibre Reinforced Plastics Strand Sheets Bonded to Steel Beams

Corrosion of steel structures is unavoidable and the structural performance decreases dramatically due to the corrosion. As a repairing method for corroded steel members, bonding carbon fiber sheets with resin had been developed. The purpose of this study is to propose the flexural strengthening method for steel members by using CFRP （carbon fiber reinforced polymer） strand sheets. In order to clarify the stiffening effect and the debonding characteristics of CFRP strand sheets, and to optimize the strengthening design specifications, the flexural tests using high tension steel beams strengthened with CFRP strand sheets are performed. Two cases of experiments are carried out. In Experiment 1, the result from previous research is reflected in the strengthening design. Moreover in Experiment 2, the debonding characteristics obtained from Experiment 1 are reflected. As a result, it was clarified that CFRP strand sheets have stiffening effect equivalent to the theoretical value and its debonding property is practically high enough when FRP （fiber reinforcement polymer） sheets have an appropriate bonding length.

纤维素的降胆固醇作用

羟丙甲基纤维素(HPMC)是木浆中所含纤维素的衍生物,常用作食品增稠剂,如干酪、蛋糕、布丁等。也可用于药品中,作为结合剂或分散剂。最近美密西根大学用它做胃肠粘性试验时,偶然发现它有降低胆固醇的作用。接着又专门做了几次人群试验,并得到进一步证实。

On determination of the damping factor of linear viscoelastic materials using dynamic indentation:a theoretical study

In this study,we theoretically investigate the dynamic indentation for measuring the loss (damping) factor of a linear viscoelastic material from its indentation response.A rigid indenter with arbitrary tip profile is assumed to indent into a viscoelastic substrate with arbitrary shape.We perform a theoretical analysis and identify the conditions under which the loss factor of the material can be determined from the phase angle between the applied harmonic indentation load and the corresponding harmonic displacement,a directly measurable quantity in a dynamic indentation test.To validate the conclusion drawn from our theoretical analysis,a series of numerical experiments are performed,including the spherical indentation of a soft layer with irregular surface morphology bonded to a rigid substrate,a conical indenter with tip defects indenting into a half-spherical particle,and the indentation of porous materials.This study may facilitate the use of the dynamic indentation technique to evaluate the damping properties of linear viscoelastic materials,including some advanced polymers and biological soft tissues.

Experiments on and predictions about properties of sand bonded by microbe cement

Microbe cement as a new bonding material is presented. Sandstone （0.05 m diameter, 0.5 m height） and sandpile （0.125 m^3） are joined by microbe cement to make a whole body. Evolutions in the related properties of treated sand samples are examined through compressive strength and calcite content. Results indicate that the structure of the cemented body is nonuniform, that the calcite content decreases with distance from the injection port, and that the compressive strength also decreases with dis- tance from the injection port. In addition, evolutions in the measured calcite content and compressive strength are summarized by a numerical model that considers microbe concentration distribution. The numerical results of the calcite content at different positions for 0.5 m height sandstone are similar to the test results, and the experimental results for calcite content and compres- sive strength of 0.125 m^3 cubic sandpile are similar to the numerical results. Prediction results indicate that the simulations should become a significant supplementary tool when microbe cement is applied in actual engineering projects.

An oversize correction method of dry density for non-cohesive soils filling the embankment of high-speed railway

Non-cohesive soils have been widely used in construction of high-speed railway for their excellent physical and mechanical properties,and the determination of maximum and minimum dry density of such soils containing oversize particles is an important topic.In this study,the influence of oversize particles on dry density of non-cohesive soils is investigated by packing tests.Test results show that oversize particles will make"extra"voids around their surfaces,which increase significantly if the size ratio of oversize material to matrix material is not very big.The dry density of the total material will be overestimated by Elimination Method due to the omission of the"extra"voids.Thus,a geometric model is proposed by which the"extra"voids can be taken into account,and a new oversize correction method for non-cohesive soils is developed.Test results confirm the applicability of this method on the condition of oversize fraction being less than 40%by mass.