Carbonation Behavior of Engineered Cementitious Composites under Coupled Sustained Flexural Load and Accelerated Carbonation

Engineered cementitious composites (ECCs) belong to a broad class of fibre-reinforced concrete. They incorporate synthetic polyvinyl alcohol (PVA) fibres, cement, fly ash and fine aggregates, and are designed to have a tensile strain capacity typically beyond 3%. This paper presents an investigation on the carbonation behaviour of engineered cementitious composites (ECCs) under coupled sustained flexural load and accelerated carbonation. The carbonation depth under a sustained stress level of 0, 0.075, 0.15, 0.3 and 0.6 relative to flexural strength was measured after 7, 14 and 28 days of accelerated carbonation. Thermogravimetric analysis, mercury intrusion porosimetry and microhardness measurements were carried out to show the coupled influence of sustained flexural load and accelerated carbonation on the changes of the mineral phases, porosity, pore size distribution and microhardness along the carbonation profile. A modified carbonation depth model that can be used to consider the coupled effect of flexural tensile stress and carbonation time was proposed. The results show that an exponential relationship can be observed between stress influence coefficient and flexural tensile stress level in the carbonation depth model of ECC, which is different when using plain concrete. Areas with a higher carbonation degree have greater microhardness, even under a large sustained load level, as the carbonation process refines the pore structure and the fibre bridges the crack effectively.     

Effects of Achieving SVR on Clinical Characteristics and Surgical Outcomes in Patients Who Developed Early-Stage HCV-Related Hepatocellular Carcinoma and Received Curative Resection: Preoperative versus Postoperative SVR

The high accessibility to healthcare and increasing awareness of hepatocellular carcinoma (HCC) surveillance after sustained virologic response (SVR) to HCV treatment allow early detection of operable HCC in Taiwan. However, the effects of achieving SVR on patient characteristics and surgical outcomes after curative resection remain elusive. We aimed to compare the clinical presentation and postoperative prognosis among patients with early-stage HCV-related HCC and different viral status. We retrospectively analyzed 208 patients with BCLC stage 0 or A-HCC, including 44 patients who remained HCV viremic, 90 patients who developed HCC after achieving SVR (post-SVR HCC), and 74 patients who subsequently achieved SVR after resection. Patients with post-SVR HCC had a lower degree of hepatitis and better liver function than those who achieved SVR or remained viremic after resection. Notably, 75.6% of patients with post-SVR HCC did not have cirrhosis. Patients with post-SVR HCC and those achieving SVR after resection exhibited comparable recurrence rates and recurrence-free survival, while patients with persistent viremia had the worst surgical outcomes. We concluded that patients with post-SVR HCC had a better liver function but similar surgical outcomes compared with patients who achieved SVR after resection. The low prevalence of cirrhosis in patients with post-SVR HCC highlights the importance of regular surveillance after SVR.     

Influencing factors and hemodynamic study of initial and sustained orthostatic hypotension in middle‐aged and elderly patients

Orthostatic hypotension (OH) is a common autonomic disorder. This study aimed to investigate the influencing factors and hemodynamic mechanisms of initial and sustained OH in middle‐aged and elderly patients. The authors analyzed the clinical characteristics and hemodynamic variables of patients aged ≥ 50 years according to the various forms of OH, diagnosed by an active orthostatic test using the CNAP monitor. The study included 473 participants; 119 (25.2%) patients had initial (54, 45.4%) or sustained (65, 54.6%) OH. Age, comorbidities, or medications did not differ significantly between the initial OH and non‐OH groups. Sustained OH was associated with age and diabetes (p = .003 and p = .015, respectively). Hemodynamic analysis revealed higher cardiac output (CO) in the sustained OH group within 15 s than in the non‐OH and initial OH groups (both p < .001); no difference in CO was observed between the initial OH and non‐OH groups. The systemic vascular resistance (SVR) in both initial OH and sustained OH groups within 15 s was lower than that in the non‐OH group (both p < .001). No differences in SVR at 3 min were observed between the initial OH and non‐OH groups. The SVR at 3 min in the sustained OH group was significantly lower than in non‐OH and initial OH groups (both p < .001). Age and diabetes emerged as the independent risk factors associated with sustained OH. Initial OH is associated with a mismatch of increase in CO and decrease in SVR. Sustained OH is mainly associated with sustained inadequate adjustment in SVR.     

养阴清肺汤加味治疗喉源性咳嗽

目的观察养阴清肺汤加味治疗喉源性咳嗽的疗效。方法 147例喉源性咳嗽患者,随机分为治疗组和对照组。治疗组运用养阴清肺汤加味治疗75例,并设西药(头孢克洛缓释片和复方甘草片)对照组72例。分别治疗2个疗程。结果治疗组有效率90.7%,对照组有效率80.6%,2组比较存在统计学意义(P<0.05)。结论养阴清肺汤加味治疗有疏表宣肺、化痰止咳的作用,可从多方面、多环节发挥治疗作用。     

丹参素钠-PLGA缓释微球的制备及药剂学性能评价

目的:优选丹参素钠-聚乳酸-羟基乙酸共聚物(PLGA)缓释微球的处方工艺并考察其药剂学性能。方法:采用W/O/O型乳化溶剂挥发法制备丹参素钠-PLGA微球,以载药量、包封率及收率为考察指标,通过单因素试验优选处方工艺,并考察其体外释药性能。采用激光粒度分析仪、扫描电子显微镜和X射线衍射法对该微球进行表征。结果:选取内水相体积300μL,PLGA质量浓度125 g·L~(-1),二氯甲烷-丙酮(3∶7),外油相为液体石蜡200 m L,加入正己烷6 m L,0.25%司盘80为乳化剂,1 400 r·min~(-1)搅拌4 h。丹参素钠-PLGA微球平均载药量(20.71±1.42)%,平均包封率(63.27±1.70)%,平均收率(99.10±0.83)%,体外累积释放率达98%需要120 h。平均粒径(71.72±1.71)μm,表面圆整光滑,内部含有蜂窝状孔洞。部分药物可能以晶体状态分散于载体材料中。结论:W/O/O型乳化溶剂挥发法成功制备了丹参素钠-PLGA微球,优选的处方工艺稳定合理,可为丹参素钠制剂的开发提供参考。     

乙基纤维素水性包衣技术I.水分散体与有机溶液包衣方法的比较

考察了乙基纤维素水分散体的基础性质,测定ＰＨ值、粘度、最低成膜温度、玻璃化转变温度,进行了处方相容性试验。以盐酸苯丙酸胺为模型工物,在流化床中蛊缓释微丸,考察在纤维素水分菜体的包衣应用特点,并与有机溶液包衣方法在缓释效果,增塑剂用量、包衣喷液方式的影响三方面进行比较。考察了水分菜体包衣微丸的稳定性,采用相似因子法评价微丸的体外释放度变化。     

蒿甲醚固体分散体缓释制剂的研制及其体外溶出度的观察

本实验以肠溶材料丙烯酸树脂Ⅱ号为载体制成蒿甲醇的固体分散体。X射线衍射实验表明，药物与载体比例为1：2和1：3时，药物在固体分散体中改变了晶型。体外溶出实验说明，固体分散体在pH0．8人工肠液中溶出量较蒿甲醚原粉大为增加。结果表明：蒿甲醚固体分散体缓释制剂既可增加溶解度，提高药物的生物利用度，又达到缓释的目的。     

抗生素缓控释给药系统——载药微球的研究与开发

利用具良好生物相容性和生物可降解性的聚合物制得的微球作为一种新型药物载体,具有良好的缓控释作用,并具有一定的靶向性,可用于口服和注射,在药学领域和临床上有着广阔的应用前景。综述近年来各种抗生素缓控释微球制剂的研究与开发。     

基于药物仿生系统分析雷公藤双层片的释药特征

目的: 应用药物溶出/吸收仿生系统(DDASS)研究雷公藤双层片的体外释放和跨膜透过特征,并考察其与该制剂在Beagle犬体内过程特征的体内外相关性。 方法: 以雷公藤定碱为指标成分,考察雷公藤片及雷公藤双层片在转篮法中的释药特征,研究其在DDASS模型体外连续、动态、实时的释放和跨膜透过特征;考察2种制剂在Beagle犬体内的药代动力学特征及其相应的体内外相关性。 结果: 雷公藤双层片中雷公藤定碱在转篮法和DDASS中释药过程均符合一级动力学方程,呈溶蚀释放机制。与雷公藤片相比,雷公藤双层片中雷公藤定碱在Beagle犬体内具有明显的缓释作用,相对生物利用度174.88%。在DDASS模型释放/跨膜透过特征与Beagle犬体内吸收特征存在极显著的相关性,优于转篮法溶出特征与Beagle犬体内吸收特征之间的相关性。 结论: DDASS模型可有效评价雷公藤双层片中雷公藤定碱的体外释放及体内吸收动力学特征。     

柱前手性衍生化反相高效液色谱分离酮洛芬对映体

 目的：建立柱前手性衍生化反相高效液相色谱法分离酮洛芬对映体的方法。方法：分别以二氯亚砜和1,l′-羰基二咪唑为酰化剂,R-(+)-a-甲基苄胺作为柱前手性衍生化试剂,甲醇-0.025 mol·L〈sup〉-1〈/sup〉,磷酸二氢钾溶液(70：30)作流动相,在Shim-Pack LC-ODS柱上反相色谱分离酮洛芬对映体衍生物,柱温,室温。结果：在选定的条件下,酮洛芬的对映体衍生物得到分离,并确认了R-(一)-和S-(+)-两个衍生物的色谱峰。结论：通过统化,再以R-(+)-a-甲基苄胺为柱前手性衍生化试剂,用反相色谱法,实现了对酮洛芬对映体的分离。