氯吡格雷临床研究出血事件综述

P2Y12受体拮抗剂是目前治疗急性冠状动脉综合征常用药物之一，氯吡格雷是P2Y12受体拮抗剂中的代表药物，出血事件作为该药最常见的副作用也一直受到关注。本文对氯吡格雷大型临床研究中出血事件的发生率及风险进行分析和探讨，为临床上合理处方氯吡格雷提供参考。     

急性冠脉综合征患者接受经皮冠状动脉介入治疗前后抗凝策略

急性冠脉综合征(ACS)是一组由急性心肌缺血引起的临床综合征,包括不稳定型心绞痛(UA)、非ST段抬高型心肌梗死(NSTEMI)和ST段抬高型心肌梗死(STEMI)。目前抗血小板治疗和抗凝治疗是ACS患者抗栓治疗的两大重要组成部分。强力抗血小板及抗凝药物的出现,在很大程度上减少了ACS患者缺血事件的发生率,但经皮冠状动脉介入治疗(PCI)围手术期抗血小板及抗凝治疗的联合应用增加了出血风险,而出血风险又增加发生死亡、心肌梗死(MI)或卒中的风险,其原因可能与输血和/或停用抗凝抗血小板药物有关。因此,权衡抗栓效应及出血风险可进一步改善ACS患者临床疗效。本文就ACS患者有关接受PCI前后的抗凝治疗策略的一些大型临床试验及抗凝药物在当今早期侵入性冠状动脉治疗时代中的应用现状作一综述。     

Corrosion and chemical behavior of Mg97Zn1Y2-1wt.%SiC under different corrosion solutions

To explore the corrosion properties of magnesium alloys, the chemical behavior of a high strength Mg₉₇Zn₁Y₂-1 wt.%Si C alloy in different corrosion environments was studied. Three solutions of 0.2 mol·L^-1 NaCl, Na₂SO₄ and NaNO₃ were selected as corrosion solutions. The microstructures, corrosion rate, corrosion potential, and mechanism were investigated qualitatively and quantitatively by optical microscopy(OM), scanning electron microscopy(SEM), immersion testing experiment, and electrochemical test. Microstructure observation shows that the Mg₉₇ Zn₁Y₂-1 wt.%Si C alloy is composed of α-Mg matrix, LPSO(Mg₁₂ ZnY) phase and Si C phase. The hydrogen evolution and electrochemical test results reflect that the Mg₉₇Zn₁Y₂-1 wt.%SiC in 0.2 mol·L^-1 Na Cl solution has the fastest corrosion rate, followed by Na₂SO₄ and NaNO₃ solutions, and that the charge-transfer resistance presents the contrary trend and decreases in turn.     

北京医院经皮冠状动脉介入治疗前后用药情况和建议

目的:主要根据经皮冠状动脉介入治疗(PCI)指南(2009),并结合最新的2012《中国经皮冠状动脉介入治疗指南》(简本)分析北京医院介入治疗前后用药情况及合理性。方法:收集2012年1月至5月北京医院心内科符合条件的冠心病患者,针对其围手术期及术后冠心病二级预防用药进行统计分析。结果:本调查共纳入冠心病患者73例,其中行冠脉造影检查44例,经皮冠状动脉介入治疗29例,患者中服用抗血小板药物的比例为100%,抗凝药物为27%,β受体阻滞剂为74%,血管紧张素转换酶抑制剂或血管紧张素Ⅱ受体拮抗剂合计为73%,调脂药物为96%。结论:国内冠心病患者围手术期及术后冠心病二级预防用药的使用状况与指南要求存在差距,如何将循证医学证据与临床实践相结合,让尽可能多的患者从中受益,仍是医生、药师和管理部门面临的现实问题。     

氟桂利嗪与阿司匹林联合应用治疗偏头痛性脑梗死

目的 探讨钙离子拮抗剂氟桂利嗪与抗血小板药阿司匹林联合应用治疗偏头痛性脑梗死的临床疗效。 方法 对诊断明确的38 例偏头痛性脑梗死患者给予氟桂利嗪10 mg 与阿司匹林100 mg 联合治疗, 两药均每晚一次, 连用1 mon。观察用药前后患者神经功能缺损程度评分及患者总的生活能力等级的改变, 同时检测用药前后患者的血小板聚集指数、血浆粘度的变化。 结果 38 例用药治疗前患者神经功能缺损程度评分及患者总的生活能力等级分别为13.51 ±4.78 分与3.45 ±1.13 级, 用药后分别为4.34 ±1.85 分与1.79 ±0.72 级, 治疗前后有显著性差异(P <0.01)。用药前血小板聚集指数与血浆粘度分别为57.1 ±19.8 与1.72 ±0.11, 用药后分别为35.12 ±7.94 与1.70 ±0.11, 治疗前后亦有显著性差异(P <0.01)。 结论 钙离子拮抗剂氟桂利嗪与抗血小板药阿司匹林联合应用治疗偏头痛性脑梗死有较好的的临床效果, 值得临床推广。     

降纤酶与其他药物治疗急性脑梗死对照研究的Meta分析

目的 了解降纤酶与其他药物治疗急性脑梗死(ACI)疗效的差异。方法 应用Meta 分析对10 项研究降纤酶与其他药物治疗ACI 的效果进行同质性检验和合并效应量的估计。结果 ①同质性检验:χ²=6.8452,自由度为9,P >0.05 。②合并效应量的估计:OR_合并=3.2353,OR_合并95%可信区间为2.21 ~4.74 。OR_合并的检验:χ²=36.2,P <0.001 。结论 降纤酶治疗ACI 的疗效显著优于目前常用药物,其在适应症、治疗剂量、给药方法及用药时限等方面与临床疗效的关系有待进一步研究。     

洛沙坦对血管紧张素Ⅱ诱导的心肌细胞c-fos表达及对细胞内游离钙升高的拮抗作用

目的 研究血管紧张素AT₁亚型受体拮抗剂洛沙坦(losartan,LT)对血管紧张素Ⅱ(AngⅡ)诱导的心肌细胞c-f os 表达及细胞内游离钙变化的影响。方法 斑点杂交及Fura-2技术。结果 AngⅡ10nmo l/L 能诱导培养乳鼠心肌细胞c-fos的一过性高表达及[Ca²⁺] 的显著升高。LT 20μmol/L能显著抑制AngⅡ诱导的心肌细胞c-fos的高表达,而血管紧张素AT₂亚型受体拮抗剂PD123319 则无明显作用。LT1~100μmol/L 能剂量依赖性地抑制AngⅡ引起的[Ca²⁺]i升高。结论 AngⅡ诱导的心肌细胞c-f os 高表达及[Ca²⁺]i升高可能是通过AT₁亚型受体介导而实现的,LT可能是一种治疗心肌肥厚的有效药物。     

阿司匹林-烟酰胺-锌络合物对血小板聚集作用和实验性血栓形成的影响

目的: 对阿司匹林-烟酰胺-锌络合物(WUY)的抗血小板聚集作用和抗实验性血栓形成作用进行研究。方法: 用 Born 法测定 WUY 对抗腺苷二磷酸钠(ADP)、花生四烯酸(AA) 和胶原诱导大鼠体外或体内血小板最大聚集, 用小鼠静注 AA 引起的死亡率以及大鼠实验性血栓形成研究药物的抗血栓作用, 并且用放免法测定家兔口服药物后血小板释放产物血栓烷 B₂ (TXB₂) 和 6-酮前列腺素 F_1α (6-keto-PGF_1α) 的含量。结果: WUY 高、中、低 3 种剂量在体外都能显著对抗诱导剂(ADP、AA 和胶原) 引起的血小板聚集, 其中高剂量组的抗血小板聚集作用比阿司匹林(ASP) 强。在体内, WUY 明显抑制 AA 诱导的血小板聚集作用, 1 h 和 3 h 作用最强。WUY 对小鼠尾静脉注射 AA 后诱发的肺栓塞死亡有较强的预防作用, ED₅₀ 比ASP 低, 对大鼠实验性血栓形成也有显著的抑制作用。WUY 高剂量能显著抑制血浆中TXB₂ 水平和提高血浆中6-keto-PGF_1α 含量, 而ASP则降低血浆中 TXB₂ 和 6-keto-PGF_1α 的水平。结论: WUY 具有比ASP 更强的抗血小板聚集作用和抗实验性血栓形成作用, 并能提高血浆中 6-keto-PGF 1α 含量。     

不同剂量valsartan应用对SHR血压和左室心肌肥厚的影响

目的 评价不同剂量AT₁受体拮抗剂valsartan 对SHR 的降压疗效及其逆转心肌肥厚作用的影响。方法 18 只14 周龄雄性SHR 随机分成空白对照组、小剂量valsartan 组、大剂量valsartan 组, 另设WKY 正常对照组, 分别给予生理盐水、valsartan 8mg·kg^-1、valsartan 24 mg ·kg^-1, 每日1 次灌胃给药, 持续8 wk 。结果 药物干预各组SHR 动脉收缩压(SBP)水平明显下降, 尤以大剂量valsartan 组SBP 下降最显著;药物干预各组LVM/BW、TDM均明显减低。结论 不同剂量AT₁ 拮抗剂均有明显的降低SHR 的SBP 作用, 能明显抑制左室肥厚进展;大剂量用药效果最为显著。     

氯吡格雷在急性冠状动脉闭塞介入治疗中的疗效与安全性评价

目的 观察氯吡格雷在急性冠脉闭塞介入治疗中的疗效和安全性。方法 选择急性冠脉闭塞接受介入治疗的患者92 例,随机分为氯吡格雷组和噻氯匹定组,在常规治疗的基础上各试验药分别给予治疗,对比观察术后3 wk 血小板聚集率及临床情况、不良反应发生率。结果 两组服药后3 wk 血小板聚集率及治疗有效率无统计学差异,氯吡格雷组不良反应及停药率均显著低于噻氯匹定组。结论 氯吡格雷在急性冠脉闭塞介入治疗中的疗效与安全性优于噻氯匹定。     

On the magnetic and valence properties of Ce---Mg---Y compounds

The structural and magnetic properties of a series of novel compounds in the ternary Ce---Mg---Y system have been studied by X-ray diffraction. SQUID magnetometry and XAS spectroscopy. The crystal structures of the compounds Ce_0.34Y_0.67Mg₂ and Ce_0.49Y_0.51Mg_4.7 have been refined by the Rietveld technique. Magnetic data are consistent with a tripositive ground state ²F_5/2 for the cerium atom. The XAS measurements confirm this result. Crystal field effects are apparent in the magnetic data at temperatures below about 50 K in the compounds with higher Ce concentration.     

Red photoluminescence properties and crystal structure of sodium rare earth oxyborate

The subsolidus phase relations of the system Y₂O₃–Na₂O–B₂O₃ are reported. There are seven binary compounds and two ternary compounds in this system. A new ternary compound Na₂Y₂B₂O₇ is identified. The structure has been determined for the compound Na₂Y₂B₂O₇ from powder X-ray diffraction. The lattice constants of P2₁/c for the compound Na₂Y₂B₂O₇ are a=10.5993(1) Å, b=6.2311(1) Å, c=10.2247(1) Å, β=117.756(1)° and z=4. The structure can be described as being made up of isolated BO₃ triangles and YO₈ polyhedra. The photoluminescence properties of Eu ion-doped Na₂Y₂B₂O₇ and Na₃Y(BO₃)₂ show strong red-emission of the ⁵D₀–⁷F₂ transitions at 611 and 615 nm, respectively. The results of emission spectra are in good agreement with the crystallographic study. The relationship between Eu ion content and emission intensity is analyzed too.     

Non-isothermal Crystallization Kinetics and Isothermal Crystallization Kinetics in Supercooled Liquid Region of Cu–Zr–Al–Y Bulk Metallic Glass

The crystallization kinetics of Cu_(43)Zr_(48)Al_9and(Cu_(43)Zr_(48)Al_9)_(98)Y_2bulk metallic glasses in non-isothermal and isothermal conditions was studied by differential scanning calorimetry.In the non-isothermal and isothermal modes,the average activation energy of(Cu_(43)Zr_(48)Al_9)_(98)Y_2is larger than that of Cu_(43)Zr_(48)Al_9,meaning the higher stability against crystallization of(Cu_(43)Zr_(48)Al_9)_(98)Y_2.In addition,the average activation energies for Cu_(43)Zr_(48)Al_9and(Cu_(43)Zr_(48)Al_9)_(98)Y_2calculated using Arrhenius equation in isothermal mode are larger than the values calculated by Kissinger–Akahira–Sunose method in non-isothermal mode,indicating that the energy barrier is higher in isothermal mode.The Johnson–Mehl–Avrami model was used to analyze the crystallization kinetics in the non-isothermal and isothermal modes.The Avrami exponent n for Cu_(43)Zr_(48)Al_9is above 2.5,indicating that the crystallization is mainly determined by a diffusion-controlled three-dimensional growth with an increasing nucleation rate,while the Avrami exponent n for(Cu_(43)Zr_(48)Al_9)_(98)Y_2is in the range of 1.5–2.5 in the non-isothermal mode,implying that the crystallization is mainly governed by diffusion-controlled three-dimensional growth with decreasing nucleation rate.Finally,the Avrami exponents n for Cu_(43)Zr_(48)Al_9and(Cu_(43-)Zr_(48)Al_9)_(98)Y_2are different in the non-isothermal and isothermal conditions,which imply different nucleation and growth behaviors during the crystallization processes.     

The effect of Hf substitution for Zr on glass forming ability and magnetic property of FeCoZrMoBAlY bulk metallic glasses

Bulk metallic glasses (BMGs) Fe₆₁Co₆Zr_8−xHf_xMo₇B₁₅Al₁Y₂ (x = 0–8) have been produced by copper mold casting technique using industrial raw materials. The effect of substitution of Hf for Zr on the glass forming ability (GFA) and the magnetic property has been studied by X-ray diffraction (XRD), differential scanning calorimetry (DSC) and superconducting quantum interference device (SQUID). It was found that the substitution of an appropriate amount of Hf for Zr can improve the GFA of the base alloy Fe₆₁Co₆Zr₈Mo₇B₁₅Al₁Y₂, as demonstrated by the increase in reduced glass transition temperature T_rg (=T_g/T_l) and GFA parameters of γ (=T_x/T_g + T_l) and δ (=T_x/T_l − T_g). The Fe₆₁Co₆Zr₅Hf₃Mo₇B₁₅Al₁Y₂ alloy exhibits the highest GFA with the largest T_rg (0.612) and δ (1.633), and can cast a fully amorphous rod in 3 mm diameter. The substitution of Hf for Zr also enhances the magnetic properties, as verified by the increase in saturation magnetization (M_s) in the alloy of Fe₆₁Co₆Zr₃Hf₅Mo₇B₁₅Al₁Y₂, whose M_s is approximately 1.5 times higher than that of the base alloy (x = 0) at room temperature. Finally, the effect of the substitution of Hf for Zr on glass forming ability and magnetic properties is discussed.     

Microstructure and mechanical properties of ultrafine grained Mg97Y2Zn1 alloy processed by equal channel angular pressing

The Mg₉₇Y₂Zn₁ alloy processed by equal channel angular pressing (ECAP) has been investigated. It was found that the blocks of secondary phase were broken into uniform distributed sections after ECAP. The Mg₉₇Y₂Zn₁ alloy processed by ECAP obtained ultrafine grains and exhibits excellent mechanical properties. The average grain size of about 330 nm, yield strength (YS) of 400.3 MPa and ultimate tensile strength (UTS) of 450.0 MPa were obtained by two-step ECAP of 4 passes at 623 K and 2 passes at 603 K. The long-period stacking (LPS) structures contribute to the formation of ultrafine grains in ECAP processed Mg₉₇Y₂Zn₁ alloy. The results demonstrate that ECAP instead of rapid solidified powder metallurgy (RS/PM) can refine grain size and enhance the strength of Mg₉₇Y₂Zn₁ alloy. It was also found that the elongation of alloy is decreased with increasing pass number. It was found that cracks were preferentially initiated and propagated in the interior of X-phase during the process of ECAP.     

Comparative Study on Corrosion Behavior and Mechanism of As-Cast Mg-Zn-Y and Mg-Zn-Gd Alloys

Rare earth (RE) elements have large solid solubility in magnesium and are widely used to regulate the microstructure and property of advanced magnesium alloys. However, different kinds of RE elements have different effects on microstructure and property of the alloy. In this study, a Mg-Zn-Y alloy and a Mg-Zn-Gd alloy with alloying elements of the same atomic percentage were designed to clarify the effect of yttrium (Y) and gadolinium (Gd) on the corrosion behavior of as-cast MgZn₂Y_2.66 and MgZn₂Gd_2.66 alloys. The results show that the MgZn₂Y_2.66 alloy is mainly composed of α-Mg phase and long period stacking ordered (LPSO) phase, while MgZn₂Gd_2.66 alloy is mainly composed of α-Mg phase and (Mg, Gd)₃Zn phase (W phase). Generally speaking, the corrosion phenomena of the two alloys in 3.5 wt% NaCl solution are similar. In the early stages of exposure, the alloys underwent uniform corrosion at a relatively low corrosion rate. With prolonged exposure, localized corrosion became dominated and the corrosion rate was greatly increased. However, the corrosion rate of the MgZn₂Y_2.66 alloy, in terms of the corrosion current density, is about one order of magnitude lower than that of the MgZn₂Gd_2.66 alloy. The high corrosion resistance of the MgZn₂Y_2.66 alloy is mainly attributed to the presence of LPSO phase in form of continuous networks and the relatively high corrosion resistance of the corrosion product layer on the alloy.     

Spectroscopic and 1.06 μm laser properties of Nd-doped K–Sr–Al phosphate and fluorophosphate glasses

Optical absorption, fluorescence and decay curves for the ⁴F_3/2 level of Nd³⁺ ions in phosphate (P₂O₅–K₂O–SrO–Al₂O₃) and fluorophosphate (P₂O₅–K₂O–SrO–Al₂O₃–AlF₃ and P₂O₅–K₂O–SrO–Al₂O₃–BaF₂) glasses doped with three concentrations (0.1, 1.0 and 2.0 mol%) of Nd³⁺ ions have been investigated. The Judd–Ofelt (JO) theory has been applied to the absorption spectra of 1.0 mol% Nd³⁺-doped glasses to derive JO intensity parameters which are in turn used to calculate the radiative properties of the Nd³⁺ ion fluorescent levels. The assigned energy level data of Nd³⁺ (4f³) ions are analysed in terms of a parametrized free-ion Hamiltonian model that consists of 20 interaction parameters of atomic nature. The stimulated emission cross section and branching ratios have been calculated using the emission spectra. The relatively higher branching ratio for ⁴F_3/2 → ⁴I_11/2 transition shows the suitability of these glasses for laser application. It is interesting to note that the measured decay curves of the ⁴F_3/2 level remain nearly single exponential even for higher Nd³⁺ ion concentration but with shortening of lifetime.     

Analysis of the internal friction spectra of high purity aluminium at medium temperatures

The internal friction spectra of high purity aluminium (99.999%) has been thoroughly studied but, at the present time, there is no agreement about the number of peaks at medium temperatures and the number of components of each peak. This paper discusses the reasons for that controversy and summarizes the relaxation processes found in the internal friction spectra. Some authors have assumed that the P₂ peak (also called Kê peak) is formed by two components, one associated to a mechanism of dislocation mobility and the other to grain boundary sliding. However, this assertion is based on weak experimental evidence, which is critically reviewed in this work. The fitting methods used to decompose the internal friction spectra have also been discussed, since some of them can generate spurious components and lead to equivocal conclusions. Another point of great interest that has remained unclear concerns the shifts of the temperature of the peaks observed by many authors, which are explained in this paper with the help of some mechanisms of dislocation mobility. Several specific experimental measurements in 99.999% aluminium and 99.9999% aluminium doped with 10 ppm of copper are presented to clarify these questions. It is concluded that P₂ is composed of just one component and is associated to a mechanism of dislocation mobility. In addition, we have determined that there are only three peaks in the medium temperature range, namely P₁, P₂ and P₃.