Combination of thymosin α1 with conventional therapy improves APC and IL-1R1 levels in children with severe pneumonia

Purpose: To investigate the effect of a combination of thymosin α1 with  conventional regimen on APC and IL-1R1 levels in children with severe pneumonia, and to provide a reference for its clinical treatment.Methods: A total of 96 children with severe pneumonia over a period of two years were divided into control and observation groups (48 cases per  group) by random number table method. The patients consisted of 46 males and 50 females within the age range of 0.1 - 6 years (mean age = 3.0 ± 1.2 years), and mean duration of 13.4 ± 2.2 days). Their acute physiology and chronic health evaluation II (APACHE II) was 20.3 ± 3.2 points. Patients in the control group were placed on conventional treatment programs, while those in the observation group, in addition to the  conventional treatments, received thymosin α1 (subcutaneous injection of thymosin α1 at a dose of 1.5 mg per injection) twice daily for the first 3 days, then once daily until the 7th day, after which the adverse reactions were observed and treated. Pulmonary function indices, and levels of APC, and IL-1R1 were also determined in the patients’ sera before and after the treatment regime.Results: The clinical efficacy of the observation group was significantly better (p < 0.05) than that of control. There were no significant differences (p > 0.05) in the indices of pulmonary function (maximal inspiratory and expiratory pressure, and peak expiratory flow) between the two groups before treatment. However, after treatment they were significantly higher (p < 0.05) in the observation group than in control. There were no significant differences (p > 0.05) in APC and IL-1R1 levels between the two groups before treatment, but after treatment, while the level of APC in the observation group was significantly increased (p < 0.05), the IL-1R1 level was significantly decreased (p < 0.05), when compared to the control group. Both groups showed no obvious adverse reactions during the treatmentregime.Conclusion: Combining thymosin α1 with routine treatment in the  management of children with severe pneumonia can significantly alleviate the symptoms of patients, greatly stimulate recovery of pulmonary function, improve APC and IL-1R1 levels, and prevent inflammation.Keywords: Pneumonia, Thymosin α1, Routine treatment, Inflammatory factors, Pulmonary functio

Self-assembling subnanometer pores with unusual mass-transport properties

A long-standing aim in molecular self-assembly is the development of synthetic nanopores capable of mimicking the mass-transport characteristics of biological channels and pores. Here we report a strategy for enforcing the nanotubular assembly of rigid macrocycles in both the solid state and solution based on the interplay of multiple hydrogen-bonding and aromatic π − π stacking interactions. The resultant nanotubes have modifiable surfaces and inner pores of a uniform diameter defined by the constituent macrocycles. The self-assembling hydrophobic nanopores can mediate not only highly selective transmembrane ion transport, unprecedented for a synthetic nanopore, but also highly efficient transmembrane water permeability. These results establish a solid foundation for developing synthetically accessible, robust nanostructured systems with broad applications such as reconstituted mimicry of defined functions solely achieved by biological nanostructures, molecular sensing, and the fabrication of porous materials required for water purification and molecular separations

Influences of formation water invasion on the wellbore temperature and pressure in supercritical CO2 drilling

Aiming to study the influence of formation water invasion on the wellbore temperature and pressure in SC-CO2 (supercritical CO2) drilling with coiled tubing, this paper builds up a wellbore flow model with formation water invasion in SC-CO2 drilling with coiled tubing, based on the comprehensive investigation of the influence of viscosity, density, thermal conductivity, isobaric heat capacity and Joule-Thompson coefficient of SC-CO2. The wellbore temperature and pressure distribution were calculated by the method of coupling among these parameters. The results show that the bigger the rate of invaded formation water and the bigger the density of mixed fluid, the bigger the convective heat transfer coefficient in the annulus. Because of the Joule-Thompson cooling effect caused by nozzle throttling, the annulus Mixed fluid density increased abruptly and the convective heat transfer coefficient decreased abruptly at the well depth of about 1 900 m (about 100 m to bottom hole). Meanwhile the wellbore fluid temperature increased with the invasion rate of formation water, and the same Joule-Thompson cooling effect caused the wellbore fluid temperature to decrease abruptly at the well depth of about 1 900 m. Moreover, the wellbore annulus pressure increased with the increasing of invaded formation water quantity. But the amplitude is not obvious. Key words: coiled tubing, supercritical CO2 drilling, formation water invasion, wellbore temperature, wellbore pressur

Numerical simulation of the cutting-carrying ability of supercritical carbon dioxide drilling at horizontal section

The density of supercritical carbon dioxide is relatively heavy, close to liquid density; its viscosity is small and close to gas viscosity. In order to research the cutting-carrying ability of supercritical carbon dioxide drilling in horizontal section, a mathematical model was built describing cutting-carrying process in the horizontal eccentric annulus with supercritical carbon dioxide; at the same time, the physical model was built according to the characteristics of horizontal eccentric annulus. The cutting-carrying law in horizontal section at different viscosities and densities of supercritical carbon dioxide was simulated with CFD simulation software. The cutting-carrying ability of supercritical carbon dioxide increases with increasing density and viscosity, but there exists a critical density, when the density of supercritical carbon dioxide is smaller than that, the cutting-carrying ability will decrease apparently, and the smaller the density of supercritical carbon dioxide is, the worse the cutting-carrying ability will be. We can control the back pressure of wellhead to change the density of supercritical carbon dioxide in the wellbore while drilling and to comply with the cutting-carrying request, but the ground pump pressure should be appropriate to avoid higher load. Key words: supercritical carbon dioxide, density, carrying cuttings, numerical simulation, horizontal sectio

Feasibility analysis of coiled tubing drilling with supercritical carbon dioxide

Supercritical CO2 (SC-CO2) fluid has the properties of low viscosity and high diffusion capacity near to gas, and higher density near to liquid. Compared with nitrogen, air, liquid, aerated fluid, foam and other drilling fluids, the supercritical CO2 fluid has a wide range of density which can not only allow it to generate enough torque to run a downhole motor, but also ensure the downhole condition is in an underbalanced state while drilling. Even if the supercritical CO2 fluid invades into reservoir, the reservoir will not be damaged, on the contrary, it can increase the reservoir porosity and permeability further more, reduce flow resistance, and enhance production and recovery. Meanwhile, the velocity of a supercritical CO2 jet is faster than that of water jet and the threshold pressure is lower also resulting in improved rock breaking. When the coiled tubing drilling with supercritical CO2 takes place, it can significantly decrease the coiled tubing drilling system pressure and expand the coiled tubing operating range, it is more suitable for slim hole, microhole, short radius horizontal wells, and complex structures wells. The coiled tubing drilling with SC-CO2 will bring an innovation in the drilling technology, and will become an efficient drilling technique for special reservoir development. 摘要: ： 超临界CO2流体具有接近于气体的低黏度和高扩散系数，同时具有接近于液体的高密度。与氮气、空气、液体、充气液、泡沫等钻井流体相比，超临界CO2流体的密度变化范围较宽，这一特性使得超临界CO2为井下马达提供足够扭矩的同时，还能保证井底的欠平衡状态。即使超临界CO2流体侵入储集层，也不会对其造成伤害，相反还能进一步增大储集层孔隙度和渗透率，降低流动阻力，提高采收率。同时超临界CO2射流破岩速度较水射流快得多，而且破岩门限压力也非常低，在利用连续油管进行超临界CO2喷射钻井时，可大大降低连续油管钻井系统的压力，扩大连续油管的作业范围，更适合小井眼、微小井眼、超短半径水平井、复杂结构井等钻井。超临界CO2连续油管钻井将为钻井带来一次全新的技术创新，也将成为特殊油气藏开发的高效钻井技术。图10表1参15 Key words: coiled tubing, drilling, supercritical carbon dioxide, feasibility analysi

Effects of chitosan treatment on strength and thickening properties of oil well cement

The research objectives were to investigate the influence of chitosan on strength and thickening properties of oil well cement under the downhole temperature condition. The results showed that the chitosan has the ability to increase the thickening time, but due to chelating Ca2+ ion, it may cause consistency wave at initial stage, and shorten thickening time at higher dosage and higher temperature. Chelating pretreatment will weaken the retarding effect of chitosan. Effects of LMW chitosan on strength and thickening properties are more acute than that of HMW chitosan. Because of increasing induction period, the pre-chelating LMW chitosan extends thickening time

ROCK DRILLING WITH ABRASIVE SUSPENSION SWIRLING JET AND EFFECTS OF ADDITIVE POLYACRYLAMIDE

ABSTRACT Rock drilling experiments with an Abrasive Suspension Swirling Jet (ASSJ) have been carried out under submergence. Results show that the ASSJ can improve rock drilling with 2.2 times increase in drilling-hole diameter and with 4-5 times increase in rock removal volume when compared with non-swirling jet drilling of rock under identical conditions. And with higher PAM concentration added to the fluid, the ASSJ can significantly increase drilling depth, especially when drilling at longer standoff distance. It is also shown that the mechanism of ASSJ drilling at medium pressure on hard rocks is the overall breakage of rock grains and the binding material, in which jetting abrasive particles play dominant roles. The bottom hole shape of rock drilling with the ASSJ under submergence looks like "V". The higher rock drilling efficiency of the ASSJ results from the swirling of the jet. Organized and Sponsored by the WaterJet Technology Associatio

Pressure controlling method for managed pressure drilling with supercritical carbon dioxide as the circulation fluid

Heat transfer along the wellbore was analyzed, and then a closed mathematical model, which fully couples the hydrostatic pressure, temperature, physical properties of CO2 and friction, was established to keep bottom-hole pressure constant during drilling process. Based on the pressure profile in wellbore achieved for a certain surface back pressure, a pressure controlling method for managed pressure drilling with supercritical carbon dioxide was presented. The influences of mass flow rate, well depth and inlet temperature on the annulus pressure profile and surface back pressure were investigated. The results show that, the pressure profile is almost in linear correlation with well depth in the annulus, which provides convenience for well control. The needed back pressure (applied by surface choke) decreases with increasing mass flow rate and decreasing well depth. The impact of inlet temperature on the annulus pressure profile, surface back pressure and flow friction is negligible. It also shows that the density of CO2 increases significantly and abruptly at a critical pressure. It is suggested that the storage pressure of CO2 in surface tank be larger than the critical pressure for a certain temperature. Key words: supercritical carbon dioxide drilling, managed pressure drilling, wellbore heat transfer, annulus pressure, surface back pressur