Angiopoietin-like Proteins in Colorectal Cancer—A Literature Review

Colorectal cancer (CRC) is one of the most common types of malignancy, with an annual incidence of about 10% of the total number of new cases. Despite well-developed screening tests, mortality from this type of cancer remains unchanged. Therefore, it is important to search for more accurate markers that are useful in the detection of colorectal cancer (especially in its early stages), and treatment. Angiopoietin-like proteins (ANGPTLs) are a family of eight proteins with a diversity of applications, including pro- and anti-angiogenic properties. Consequently, we performed an extensive search of the literature, pertaining to our investigation, via the MEDLINE/PubMed database. Based on the available literature, we summarize that some of those proteins are characterized by increased or decreased concentrations during the course of CRC. We can also assume that some ANGPTLs can inhibit the development of CRC, while others induce its progress. Moreover, some factors are dependent on the stage or histological type of the tumor, the presence of hypoxia, or metastases. Most importantly, some ANGPTLs can be useful in anti-cancer therapy. Therefore, further studies on ANGPTLs as potential markers of CRC should be continued.     

基于自适应自然梯度法的高斯过程磨矿粒度软测量建模

针对现有的磨矿粒度测量仪表检测周期长,难以满足实时检测的问题,结合典型两段式磨矿回路的特点,提出了基于高斯过程(Gaussian process,GP)的磨矿粒度软测量建模方法,将自适应自然梯度(adaptive natural gradient,ANG)法应用到对高斯过程超参数优化过程中,构建基于ANG-GP磨矿粒度软测量模型,并分别与BP神经网络和支持向量机软测量模型进行仿真试验的比较研究。结果表明：基于ANG-GP的磨矿粒度软测量方法优于其他2种方法,且具有较高预测精度,能有效地对磨矿粒度进行在线检测,表明了该方法的有效性。     

Research on the theory and application of adsorbed natural gas used in new energy vehicles: A review

Natural gas, whose primary constituent is methane, has been considered a convincing alternative for the growth of the energy supply worldwide. Adsorbed natural gas (ANG), the most promising methane storage method, has been an active field of study in the past two decades. ANG constitutes a safe and low-cost way to store methane for natural gas vehicles at an acceptable energy density while working at substantially low pressures (3.5–4.0 MPa), allowing for conformable store tank. This work serves to review the state-of-the-art development reported in the scientific literature on adsorbents, adsorption theories, ANG conformable tanks, and related technologies on ANG vehicles. Patent literature has also been searched and discussed. The review aims at illustrating both achievements and problems of the ANG technologies- based vehicles, as well as forecasting the development trends and critical issues to be resolved of these technologies.     

吸附式天然气储罐充放气过程的试验研究

为研制替换家庭用LPG储罐的吸附式天然气(ANG)储罐进行了对比试验。针对ANG技术在应用过程中涉及如何管理吸附热效应的问题,选择比表面积为2 074m2/g的SAC-02椰壳活性炭,容积为1.5L的柱状钢制压力容器,在15L/min的充放气流率下,测试并分析了循环换热水管布置形式、循环水温度及充放气方式变化对储罐吸附床中心温度和储罐累积充/放气量的影响。结果表明,储罐中心在布置螺旋形换热水管后的温度变化幅度比布置U形换热水管时减少约10℃,储罐总充/放气量相应增加18%和14%;储罐换热水管循环常温自来水就能有效抑制储罐吸附床的温度波动;选用多孔管充/放气可使储罐中心温度上升/下降的幅度分别减小15℃和10℃,但会造成储罐总的充放气量下降2%和7%。家庭用ANG储罐可选用自来水冷却/加热吸附床,在选择换热管和充放气时需兼顾其对储罐总充/放气量的影响。     

LNG储罐冷却过程中BOG回收量探讨

液化天然气汽车(LNGV)用于城市小轿车时,因夜间停驶或较长时间停运时,储罐内LNG的蒸发可能迫使燃料储存系统安全阀开启放气,增加小型LNGV的安全环境风险。结合LNGV燃料储存系统的主要特点,开展了低温低压下甲烷在高表面炭质吸附剂(SYJ-2)上的吸附性能研究。结果表明,在温度238～161K,压力1.5MPa下,吸附剂对甲烷的吸附量为0.16～0.3g/g,即82～153mL/mL。吸附天然气(ANG)可望用于LNGV燃料储存系统,以增加LNGV燃料储存系统的安全性。     

天然气吸附储存吸附剂成型实验研究

以粉体石油焦基吸附剂为原料,聚乙烯醇为黏结剂,采用冷压法制备型炭甲烷吸附剂。实验考察了预湿水量、PVA加入量、成型压力、成型时间等最佳成型工艺条件,测量了粉体炭与型炭床层在甲烷充气过程中的温度变化。结果表明吸附剂成型应以提高单位储存空间内的吸附剂的微孔体积为主要目标,兼顾型炭强度和成型的难易度;25℃、5.0MPa下,最佳型炭的甲烷有效释放量达169V·V-1,较粉体炭提高47%;最佳型炭的导热性能优于粉体炭,充气过程中型炭床层的温升也小于粉体炭。     

基于双位Langmuir模型活性炭的CH_4吸附特征

较之于压缩天然气存储和液化天然气存储,天然气吸附存储(ANG)方式具有能显著降低储存压力和运行成本的优点,然而,要将测定的吸附量转化为绝对吸附量,需要采用合适的模型。为了准确预测活性炭上甲烷的总储存量,采用双位Langmuir模型描述并准确预测了甲烷在活性炭上的吸附行为,误差在5%以内;进而解释了温度介于283.15～323.15 K、压力介于0.1～14.0 MPa条件下,活性炭上甲烷吸附平衡的临界点。研究结果表明:①在过剩吸附量超过极大值后,不同温度下的吸附等温线将出现交叉现象,在交叉点后,温度越高过剩吸附量越大;②甲烷的吸附相体积和气相密度,随平衡温度和压力的变化而变化,随着温度的升高,体积密度项对于绝对吸附量的贡献逐渐减小;③在343.15 K和14 MPa以下,实际吸附甲烷量超过86.9%,游离甲烷相含量低于13.1%,游离甲烷相含量的贡献率随温度的升高而逐渐增大。结论认为,该模型能快速、准确地预测真实的甲烷存储量,可以为大型天然气吸附存储技术的研究和开发提供帮助。     

粘结剂添加量及后处理条件对成型活性炭甲烷吸附性能的影响

以酚醛树脂为粘结剂进行了超级活性炭的成型,较为详细地考察了粘结剂添加量及后处理条件对所制型炭的密度、强度及甲烷吸附性能的影响,结果发现：随着粘结剂添加量的提高,所制型炭的抗压增大,比表面积减小;随着粘结剂添加量的提高,后期活化时间的减少及活化温度的降低,所制型炭的密度增大;在粘结剂添加量为３０％,活化温度为８００℃及活化时间为３０ｍｉｎ时成型活性炭对甲烷的体积吸附量达到最大。     

成型活性炭对甲烷吸附性能研究

以羧甲基纤维素、酚醛树脂及聚乙烯醇缩丁醛为粘结剂进行了超级活性炭的成型,较为详细地考察了粘结剂添加量及粘接剂种类对所制型炭的堆密度、抗压强度及甲烷吸附性能的影响。结果发现：随粘接剂含量的增大,所制型炭的抗压强度、堆密度增大,而比表面积及孔容减小,其对甲烷的吸附性能一下降趋势。在所考察的几种粘接剂中,从工程角度考虑羧甲基纤维素是比较好的一种粘接剂。