酶固化技术最新研究进展

酶的本质是一种具有催化功能的蛋白质,能影响化学反应。然而,与传统的天然酶分子比较,固化酶相对更为脆弱,而传统的有机或无机催化剂其活性则比较固定。固化酶对于优化产业生产过程非常重要,近几十年来已开发出多种新型固化酶。本文在回顾酶固定化技术最新发展的同时。着重将其最新技术分别从吸附于载体,诱惑侦查及交联等三个方面进行综述。     

用ESR能级电子饱和法早期诊断高发肿瘤研究

用顺磁共振能级电子饱和法的饱和功率点分别对健康人、肺癌、食道癌及与肺癌相关的肺结核及矽肺5.19例的人发进行测定,并与临床诊断相比较.测定结果表明,其诊断率分别为1.66,85.24%,90.48%,27.27%,及20.00%.其中肺癌、食道癌与健康人相比较,经统计处理差异显著(P<0.001).肺癌和食道癌经治疗后其饱和功率点后移,增高明显,介于10.0—24.0mW及10.0—19.9mW者分别占71.43%、71.23%.从肺癌和食道癌治疗后的典型病例所见,饱和功率点越高、疗效越好.对食道癌高发区56例调查结果表明,饱和功率点测定结果与临床诊断一致者为39.29%,排除食道癌者为60.71%.     

两种增温方式对杉木和木荷单萜烯通量及光合特性的影响

全球增温对森林生态系统碳循环产生了重要影响,而生物源挥发性有机化合物(Biogenic volatile organic compounds,BVOCs)是生态系统中生物合成的重要次生碳代谢产物。作为BVOCs的主要组成成分,单萜烯(Monoterpenes,MTs)合成与释放在森林生态系统碳循环过程中有重要作用。以南亚热带常见树种杉木(Cunninghamia Lanceolata(Lamb.) Hook)和木荷(Schima superba Gardn.et Champ)2年生盆栽苗木为对象,设置未增温、电热线增温和红外辐射器增温3个处理,分析不同增温方式对植物MTs通量、光合作用及相关酶活性的影响。结果表明:杉木MTs通量显著高于木荷,分别为4027.634-16239.608 pmol m^-2 s^-1、49.228-130.512 pmol m^-2 s^-1。电热线增温导致杉木MTs通量增加约2倍,以柠檬烯和γ-松油烯为主,分别占73.3%和15.1%;红外辐射器增温处理下杉木MTs通量下降52.6%,以柠檬烯和α-松油烯为主,分别占71.3%和18.9%。不同处理间杉木气孔导度的变化趋势与其MTs通量结果类似,增温可能主要通过影响植物气孔导度从而影响MTs释放。增温处理后木荷净光合速率增加,其中电热线增温处理效果更显著(9.890 μmol CO₂ m^-2 s^-1),且不同处理存在显著性差异(P<0.05)。因此,在进行全球增温模拟研究时需考虑增温方式差异,建议尽量设置多种增温方式,以便更全面反映增温的生态效应,为全球增温模型提供更可靠的数据支撑。     

于家沟遗址鸵鸟蛋皮的人类利用特征

鸵鸟蛋皮是中国北方旧石器时代遗址中最常见的鸟类遗存。目前,限于蛋皮的样本量与保存状况,很少有研讨古人类是否能够食用鸵鸟蛋液或者利用鸵鸟蛋作为盛煮容器问题。本文以于家沟遗址第3b和4层出土的鸵鸟蛋皮为材料,从其¹⁴C年代、孵化状况、燃烧导致的颜色变化等方面,分析了古人类获取、消费和利用鸵鸟蛋的方式。结果显示,于家沟人既采集了鸵鸟蛋皮作为制作装饰品的原料,也可能获取了完整鸵鸟蛋,食其蛋液,用其蛋壳,并将整蛋作为容器进行了加热。     

热效应在微生物诱变育种中的应用

本文综述了微生物诱变育种中的热效应机理及其应用研究进展。热在微生物诱变育种中具有热诱变效应和热筛选效应, 热诱变效应通过热引起DNA中G-C碱基对的置换实现, 热筛选效应可以从其他诱变剂诱变的菌体中获得更高的正向突变率。     

Introducing novel potent anticancer agents of 1H-benzo[f]chromene scaffolds,targeting c-Src kinase enzyme with MDA-MB-231 cell line anti-invasion effect

In our effort to develop novel and powerful agents with anti-proliferative activity, two new series of 1H-benzo[f]chromene derivatives, 4a–h and 6a–h, were synthesised using heterocyclocondensation methodologies under microwave irradiation condition. The structures of the target compounds were established on the basis of their spectral data, IR, ¹H NMR, ¹³?C NMR, ¹³?C NMR-DEPT/APT, and MS data. The new compounds have been examined for their anti-proliferative activity against three cancer cell lines, MCF-7, HCT-116, and HepG-2. Vinblastine and Doxorubicin have been used as positive controls in the viability assay. The obtained results confirmed that most of the tested molecules revealed strong and selective cytotoxic activity against the three cancer cell lines. Moreover, these molecules exhibited weak cytotoxicity on the HFL-1?line, which suggested that they might be ideal anticancer candidates. The SAR study of the new benzochromene compounds verified that the substituents on the phenyl ring of 1H-benzo[f]chromene nucleus, accompanied with the presence of bromine atom or methoxy group at the 8-position, increases the ability of these molecules against the different cell lines. Due to their high anti-proliferative activity, compounds 4c and 6e were selected to be examined their proficiency to inhibit the invasiveness of the highly sensitive and invasive breast cancer cell line, MDA-MB-231. The anti-invasion behaviour of these molecules against the highly sensitive, non-oestrogen, and progesterone MDA-MB-231 cell line gave rise to their decreasing metastatic effect compared to the reference drug. Furthermore, this report explores the apoptotic mechanistic pathway of the cytotoxicity of the target compounds and reveals that most of these compounds enhance the Caspase 3/7 activity that could be considered as potential anticancer agents.     

Microwave Resonant Sensor for Non-invasive Characterization of Biological Tissues

Context

Microwave sensing appears to be an open wide field to investigate medical applications, such as monitoring of vital signs (temperature, arterial pressure, …), following different kinds of pathologies (cancer, glucose level …) and aid for medical diagnosis. It offers an alternative to determine the dielectric properties of biological tissues through the development of local non-invasive and/or embedded sensors, giving thus a kind of imaging by the dielectric contrast. Moreover, RF communications links between several sensors can be developed to realize “Body Area Networks”.

超声定位穿静脉结扎对下肢静脉性溃疡术后愈合影响的临床研究

目的:观察下肢静脉性溃疡患者穿静脉功能不全情况,探讨超声定位下肢穿静脉结扎对下肢静脉性溃疡术后疗效的影响。方法:40例大隐静脉曲张患者随机分成两组:A组采用大隐静脉高位结扎、静脉腔内微波射频闭合术及超声定位穿静脉结扎治疗,B组采用大隐静脉高位结扎和静脉腔内微波射频闭合术治疗。观察两组患者治疗后静脉性溃疡的愈合时间、复发率及瓣膜功能不全穿静脉数量部位,并比较两组患者临床预后评分。结果:术前两组瓣膜功能不全穿静脉数量分别是47条和44条,两组比较差异无统计学意义(P=0.5520)。术后两组愈合时间分别是(7.5±4.389)周和(11.6±6.489)周,两组比较差异具有统计学意义(P=0.048)。两组临床预后评分分别为(2.3±0.6)分和(1.1±1.5)分,两组比较差异具有统计学意义(P=0.042)。结论:多普勒超声可有效检测定位瓣膜功能不全的下肢穿静脉,在超声定位下行大隐静脉高位结扎、静脉腔内微波射频闭合术联合穿静脉结扎治疗下肢静脉性溃疡的疗效优于穿静脉不结扎。     

微波蒸馏-顶空固相微萃取-气质联用检测鱼体中土霉昧化合物

采用微波蒸馏-顶空固相微萃取-气质联用检测鱼体中常见的两种土霉味化合物,即2-甲基异茨醇(2-MIB)和土腥素(Geosmin).研究并优化了微波蒸馏萃取过程的关键参数(微波蒸馏时间、载气流量),结果表明微波蒸馏6min、载气流70 mL/min为土霉味化合物微波蒸馏萃取的最佳条件.在此优化的条件下,土霉味化合物能够充分地从鱼体中蒸馏出来,再采用顶空固相微萃取的方法使馏分中的土霉味化合物吸附于纤维涂层上,将其在250℃高温下解吸,并用GC-MS分析.基于此测定方法,鱼肉中2-甲基异茨醇和土腥素的检测限均达到0.1μg/kg,且其在1-20μg/kg的范围内线性关系良好,相关系数R分别达到0.987、0.995.因此,用该方法分析鱼体中痕量的(ppb级)的土霉味化合物,结果可靠.