基于酪蛋白自组装法制备α-生育酚/酪蛋白纳米粒及其α-生育酚稳定性分析

采用自组装法使酪蛋白与α-生育酚形成α-生育酚/酪蛋白纳米粒并考察其稳定性。以纳米颗粒的荧光强度为指标,考察在单因素试验条件下α-生育酚与酪蛋白的结合强度。对所制备的复合纳米粒表征后以α-生育酚保留率为指标进行稳定性测试。结果表明制备纳米复合物最佳条件为组装温度37?℃、pH?6.8、α-生育酚与酪蛋白质量比1∶300,所得α-生育酚/酪蛋白纳米粒平均粒径为（135.6±13.7）nm,包封率为（97.97±7.38）%,载药量为（0.33±0.03）%。红外光谱表明α-生育酚与酪蛋白存在较强氢键作用。电镜观察纳米粒形态学结构大小均匀,呈较规则球形,且分散性较好。稳定性测试表明复合纳米粒贮存稳定性、热稳定性、冻干稳定性及抗氧化性良好。该方法不仅保护了α-生育酚,而且扩大了产品的应用范围,使其在食品加工中具有理想的应用前景。     

Effects of α′ martensite and deformation twin on hydrogen-assisted fatigue crack growth in cold/warm-rolled type 304 stainless steel

The effects of α′ martensite and deformation twin on hydrogen-assisted fatigue crack growth (FCG) were investigated in cold/warm-rolled type 304 stainless steel in 5 MPa hydrogen and argon gas atmosphere. The rate of FCG is reduced in argon gas, while greatly enhanced in hydrogen gas after cold-rolling. The FCG rates of warm-rolled specimens, no matter tested in hydrogen gas or argon gas, are reduced comparing with as-received specimens. After cold-rolling, α′ martensite formed around the grain boundary promotes hydrogen-assisted crack initiation and propagation. The deformation twin plays an important role during FCG besides α′ martensite after warm-rolling, and hydrogen-assisted cracking along the twin boundary and slip band can enhance the FCG rate during cycle loading.     

α-甲基苯乙烯对ABS树脂耐热改性的研究

采用乳液聚合的方法合成了一系列α-甲基苯乙烯(α-MSt)/苯乙烯(St)/丙烯腈(AN) (α-MSAN)共聚物,用ABS接枝共聚物与α-MSAN熔融共混制备了耐热ABS。研究了α-MSAN组成对ABS耐热性能及力学性能的影响。固定AN的含量,调整α-MSt/St配比,差示扫描量热分析发现,α-MSAN的玻璃化转变温度(Tg)随着α-MSt含量的增加呈线性增加趋势,α-MSt含量每增加10%,共聚物的Tg均提高约1-2℃;动态力学分析发现,ABS树脂的Tg随着α-MS含量的增加向高温方向移动,当α-MSt/St配比为100/0时Tg高达129. 5 C。固定α-MSt/St的配比为50/50,调整AN含量,结果发现,当AN含量为25%(质量分数,下同)时,ABS树脂的Tg可达121℃,且力学性能最佳。     

基于蕴涵算子族的模糊推理的FMP三I约束算法

提出了基于蕴涵算子族L-λ-R₀的模糊推理的思想,这将有助于提高推理结果的可靠性。针对蕴涵算子族L-λ-R₀给出了模糊推理的FMP模型的α-三I约束算法、三I约束算法,并说明其现实意义。     

TNF-α对人肺癌A549 细胞凋亡的影响

目的: 探讨TNF-α对人肺癌A549 细胞凋亡的影响;方法:培养人肺癌A549 细胞,与TNF-α(10 、100U·ml^-1)共孵育,通过Western blot 分析P53 蛋白表达的变化,同时利用Annexin V/PI 双染色流式细胞仪,检测人肺癌A549 细胞凋亡率的变化。结果: 与空白组相比,TNF-α组的P53 蛋白表达明显升高,且细胞凋亡率也明显升高,分别为1.22±0.62 和1.65±0.38(P<0.01)。结论: TNF-α可以诱导人肺癌A549 细胞凋亡,从而可能起到抗肿瘤的疗效。     

N-乙酰半胱氨酸治疗慢性阻塞性肺疾病患者疗效和作用机制研究

目的: 探讨N-乙酰半胱氨酸(NAC)治疗慢性阻塞性肺疾病(COPD)的临床疗效和作用机制。方法: 将78 例COPD 患者随机分为治疗组和对照组,观察其治疗前后对痰液炎症细胞计数及核因子-kB(NF-kB)、白细胞介素8(IL-8)、肿瘤坏死因子α(TNF-α)水平的影响,以及对临床症状、肺功能指标和血丙二醛(MDA)、全血超氧化物歧化酶(SOD)和血清血管紧张素Ⅰ转换酶(ACE)活性及血内皮素-1(ET-1)含量的变化情况,并与20 名健康人作比较。结果: 78 例COPD 患者中脱落5 例(治疗组3 例,对照组2例)。NAC 治疗COPD 的总显效率为72.50 %,总有效率为87.50 %,与对照组比较有显著性差异(P<0.05)。与对照组比较,治疗组能明显改善肺功能指标(FEV1 、FVC 、mPAP)和血MDA 、SOD 、ACE 活性及ET-1 含量(P<0.05)。治疗后治疗组痰液中性粒细胞(PMN)、非中性粒细胞(mPMN);IL-8 、TNF-α和NFkB活性(A 值)较治疗前显著降低(P<0.01),降低作用优于对照组(P<0.05),治疗期间未见明显毒副作用。结论: NAC 治疗COPD 患者可改善其临床症状和肺功能,安全性良好,通过增强抗氧化能力和减轻COPD 患者气道炎症反应而发挥其治疗作用。     

IN SITU OBSERVATION ON FORMATION OF BASKET DURING BAINITIC TRANSFORMATION

By means of riM-190 hot-stage microscopy,the in situ observation of α-β transformation in12Cr2MoWVTiB steel has been carried out.The sequence of the growth of ferritic needlescomposing bainitic basket has also been determined.According to the crystallographic analy-sis a multislip system transform model concerning the formation of basket has been proposed.     

ON THE ORDERING TRANSFORMATIONS IN Ti_3AL-Nb ALLOY

Study was made of the behaviour of ordering transformation in Ti_3AI-Nb alloy,including the ordering at high temperatures,the transformation of high temperature β-phase during cooling,and the decomposition of metastable β-phase during aging.The results show that the ordered primary α_2 and high temperature β in alloy form at 1060℃.The transformation of high temperature β-phase proceed by β→α_2+ω type during cooling,and the decomposition of metastable β and ω type proceeded by(β+ω)_(metustabte)→(α_2+β)_(stable)during aging at 700℃.