Study of Mechanical Properties and Durability of Alkali-Activated Coal Gangue-Slag Concrete

Herein, a new geopolymer is recognized as a potential alternative cementing material of ordinary Portland cement (OPC), which is used for reducing carbon emissions and efficiently recycling the waste. Therefore this paper mainly studied the alkali-activated coal gangue-slag concrete (ACSC) was prepared by using the coal gangue-slag and Na₂SiO₃ and NaOH complex activator. The ratio of coal gangue (calcined and uncalcined) coarse aggregate replacing the gravel was 0%, 30%, 50%, 70%, and 100%. The water and salt freeze-thaw resistance, compressive strength, chloride permeation, microstructure, performance mechanism, inner freeze-thaw damage distribution, and mechanics models of ACSC were investigated. Results show that ACSC displayed excellent early age compressive strength, and the compact degree and uniformity of structure were better compared with the ordinary Portland cement (OPC) when the coal gangue replacement rate was less than 50%. The ACSC demonstrated the best chloride penetration resistance under 30% uncalcined coal gangue content, which was less than 27.75% lower than that of using OPC. At the same number cycles, especially in the salt freezing, the calcined coal gangue had lowered advantages of improving resistance freeze-thaw damage resistance. Water and salt accumulative freeze-thaw damage mechanics models of ACSC were established by using the relative dynamic elasticity modulus. The exponential function model was superior to the power function model with better precision and relativity, and the models accurately reflected the freeze-thaw damage effect.     

Change of Mechanical Properties of Repair Mortars after Frost Resistance Rests

The use of repair mortars for concrete structures repair with no or limited resistance to the impact caused by freeze and thaw cycles is often the primary repair failure cause. This is particularly important in Poland. Due to the geographical location of the country, there is a large temperature difference between summer and winter. The number of passes through the threshold temperature of 0 °C throughout the year in the winter season exceeds 100. The article presents a comparison of the frost resistance results of tests of repair mortars. The first method was performed according to the Polish Guidelines (without the use of de-icing salts) and the second method according to PN-EN 1504-3 (with the use of de-icing salts). The results obtained were inconsistent in many areas. In particular, significant differences in the results for the change in compressive strength and the change in bending strength were observed. In the case of the frost resistance testing without the use of de-icing salts, a decrease in compressive strength was usually accompanied by a decrease in bending strength. In the case of frost resistance tests with the use of de-icing salts, an increase in the bending strength of mortars was observed (even by a dozen or so percent) with a decrease in the compressive strength of mortars (even by several dozen percent).     

新鲜冰冻血浆不同解冻方式的凝血试验分析

目的:探讨新鲜冰冻血浆(FFP)在电热恒温水浴箱和数控冷冻血浆干式解冻仪解冻后凝血因子检测指标的变化,保证临床输血的有效性和安全性。方法:将保存3个月的同一献血者分离的2份FFP分别用电热恒温水浴箱和数控冷冻血浆干式解冻仪解冻,测定其完全解冻时间、凝血酶原时间(PT)、活化部分凝血活酶时间(APTT)、凝血酶时间(TT)、纤维蛋白原(FIB),并进行统计学分析。结果:数控冷冻血浆干式解冻仪与电热恒温水浴箱在解冻时间、APTT测定上差异有统计学意义(P0.05);其他凝血因子指标PT、TT、FIB差异无统计学意义(P0.05)。结论:FFP用数控冷冻血浆干式解冻仪解冻优于电热恒温水浴箱,可以提高输血的安全性和有效性,值得推荐使用。     

Study of coagulation function in thawed apheresis plasma for photochemical treatment by amotosalen and UVA

Background and Objectives  Photochemical treatment (PCT) based on amotosalen and ultraviolet A light (UVA) demonstrated a wide range of pathogen inactivation. However, coagulation proteins are affected by this treatment. The aim of this study was to evaluate the coagulation parameters in apheresis plasma units after thawing and processing by PCT.
Materials and Methods  Thirty apheresis plasma units were rapidly frozen at ≤ –30°C after collection. Plasma units were thawed after 7 days for PCT with amotosalen and UVA light. Treated apheresis units were refrozen and stored at ≤ –30°C for 1 month. Samples were collected for each plasma units at several times of process. Coagulation times (prothrombin time, activated partial thromboplastin time), coagulation factors (fibrinogen, Factor [F] II, FV, FVII, FVIII, FIX, FX, FXI), prothrombin fragments 1 and 2, antithrombotic proteins (protein C, protein S, antithrombin) and total protein content were measured. Functionality of ADAMTS-13 was also tested.
Results  After thawing, coagulation times were slightly increased and a decrease of FV, FVIII and protein C activity was found. The mean recovery for all proteins, except one, ranged from 81% to 97% of the baseline activity in plasma units after thawing and PCT. FVIII was more affected with a mean recovery of 69 ± 8%. ADAMTS-13 function was also preserved after the whole process. The effect of an additional 1-month frozen storage on coagulation parameters was minimum.
Conclusion  Coagulation protein levels after thawing and processing of plasma by PCT with amotosalen and UVA were preserved well in the physiological ranges.     

Abnormal Property of Human Mutant Hypoxanthine-Guanine Phosphoribosyltransferase: Insensitivity of Fibroblast Enzyme to Stabilization against Freezing and Thawing by 5-Phosphoribosyl-1-Pyrophosphate

Abstract. Freezing and thawing of dilute normal human fibroblast suspensions causes partial inactivation of hypoxanthine-guanine phosphoribosyltransferase (HGPRT) and adenine phosphoribosyltransferase (APRT). Phosphoribosyl-pyrophosphate (PRPP) stabilizes both phosphoribosyltrans-ferases against this inactivation. Mutant HGPRT enzymes from a patient with the Lesch-Nyhan syndrome and from a gouty patient with partial HGPRT deficiency were similarly inactivated by freezing and thawing, but only the former mutant enzyme could be stabilized by PRPP. The insensitivity of the mutant HGPRT from the patient with partial enzyme deficiency to PRPP stabilization indicates a structural enzyme alteration. The different sensitivity of the two HGPRT mutants to PRPP stabilization reflects the heterogeneity of HGPRT mutations in man.     

大肠杆菌中融合表达人β防御素-3基因的研究

目的为了在大肠杆菌中融合表达人β防御素-3基因。方法根据大肠杆菌对精氨酸密码子使用的偏爱性,设计搭桥引物,并通过PCR扩增法合成了人β防御素的全基因序列,克隆进pGEX-4T-2中构建pGEX-4T-2-hBD-3融合表达载体。将表达载体转化E.coli宿主菌DH5α,进行IPTG诱导表达。将菌体反复冻溶使细胞膜穿孔,释放可溶性蛋白。融合蛋白GST-hBD-3经凝血酶切割。结果研究得到了重组人防御素蛋白,琼脂孔穴扩散抑菌法检测表明,重组人β防御素3对金黄色葡萄球菌有抗菌活性,抑菌效价为0.843 U。结论人β防御素-3基因在大肠杆菌中得到了融合表达。     

Survival of Human Sperm Following Controlled- and Noncontrolled-Rate Cryopreservation/Die Überlebensrate menschlicher Spermatozoen nach einer kontrollierten und nicht kontrollierten Kryokonservierung

The purpose of this study was to develop a noncontrolled-rate (NCR) method of freezing semen in cryovials which could be used as a backup to controlled-rate (CR) freezing when the CR freezer was being utilized for freezing of human embryos or oocytes. Semen was frozen with three concentrations of glycerol (0%, 3.75%, 7.5%) in cryoprotective media in a CR freezer or using a newly developed NCR method of freezing. Semen was thawed in 40 degrees C water or in air at room temperature (RT). Controlled-rate freezing and 40 degrees C thawing resulted in significantly greater postthaw sperm motility and motility index compared with NCR freezing and RT thawing. Sperm velocity and linearity were not significantly effected by rate of freezing or thawing except when there was no glycerol present in the cryoprotective media. Postthaw motilities following CR-40 degrees C, NCR-40 degrees C, CR-RT and NCR-RT freezing-thawing were 25.6%, 24.8%, 21.6% and 18.3%, respectively. Because NCR freezing resulted in only a 0.8% decline in motility compared with CR freezing when semen was thawed at 40 degrees C it appears that this new NCR method of freezing can be successfully used as a backup to CR freezing when the CR freezer is being used for embryo or oocyte cryopreservation.     

丹参酮脂质体的药物渗漏和微粒聚结特性研究

考察了聚乙烯吡咯烷酮（PVP）以及冻融处理对丹参酮脂质体的药物渗漏和微粒聚结特性的影响。结果表明，丹参酮脂质体在4℃下贮存3、6．5个月后，未发现丹参酮有明显渗漏，处方中的PVP和冻融处理对丹参酮 的渗漏影响不明显；但PVP可提高丹参酮脂质体微粒的聚结活化能，并使脂质体ζ电位有所增大；脂质体混悬液在4℃下贮存3个月，不含PVP的样品粒度明显增大，并出现分层现象，而含有PVP的样品，其粒度变化甚微，混悬液均匀；而冻融处理也能使丹参酮脂质体的聚结活化能增大。     

冷冻保护剂对丹参酮脂质体冻融后粒度分布的影响及机理考察

考察了单糖、二糖、三糖、多醇、二甲亚砜以及高分子PVP等附加剂对冻融3次的丹参酮脂质体粒度的影响及机理，结果表明，所选附加剂均能不同程度地抑制丹参酮脂质体在冻融后粒子的显著增大，附加剂对冻融脂质体起保护作用的机理包括脂质体的静电斥力增大和附加剂的空间位阻的协同作用，以及附加剂减少了脂质体周围的冰晶等。     

IL-1对冷冻复温人精子顶体反应的影响

目的：研究复温温度和白细胞介素－1（IL－1）对冷冻精子复温后存活率和顶体反应率的影响。方法：采用精液速冻法，不同浓度IL－1作用于解冻后的精液，以三色染色法检测顶体反应率。结果：对冻融精子37℃水浴复温效果优于41℃，10ng/ml,50ng/ml IL-1可减少精子存活率和顶体反应率。结论：一定剂量IL－1可降低精子存活率和顶体反应率，可能是由于IL－1可使Na^ -K^ -ATP酶活性降低，而对丙二醛（MDA）无影响。