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1.
Phytonutrients extracted from natural resources are receiving much attention among researchers due to their highly antioxidative characteristics which prevent several degenerative diseases including cardiovascular diseases and cancers. These nutraceutical compounds can be used in food, pharmaceutical and cosmetic products as natural antioxidants, preservatives, colourants and functional foods. Huge volume of food wastes are generated from the processing industry and these low-value food residues are rich in various phytonutrients worth recovering. This approach of valorisation reduces the generation of food wastes and is cost-effective considering the cheap feedstock, reduced waste management expenses and high market value of extracted compounds. In light of the health and safety risks posed by commonly used organic extraction solvents derived from the petrochemical industry, there is a need to recover the phytonutrients using green, sustainable and efficient solvents that are safe for human consumption. This work discusses ethyl lactate as a safe, green, efficient and potentially cheap solvent to recover phytonutrients from fruit and vegetable by-products. Ethyl lactate is compared with other organic solvents commonly used from the aspects of safety, environmental impacts and efficiency. Current challenges when employing ethyl lactate are also discussed.  相似文献   
2.
目的研究并比较不同规格怀牛膝不同极性部位的HPLC指纹图谱,探索其内部质量差异,为该药材的规格标准完善及临床用药提供参考。方法将怀牛膝用体积分数75%乙醇水浴回流提取,得体积分数75%乙醇回流提取物,用40 mL水溶解后,依次用石油醚、三氯甲烷、乙酸乙酯、正丁醇进行萃取,得到各萃取相及萃取后的水相,浓缩至浸膏,采集各部位HPLC指纹图谱;运用相似度、综合聚类法进行数据分析,同时对其不同部位的指纹图谱进行比对分析。结果石油醚、氯仿部位均标定了11个共有峰,乙酸乙酯部位标定了10个共有峰,正丁醇部位标定了19个共有峰,水部位标定8个共有峰;氯仿部位指纹图谱相似度差异较大,其他部位指纹图谱相似度差异较小,均在0.9以上;石油醚部位指纹图谱差异主要体现在峰高,乙酸乙酯部位、氯仿部位、水部位的化学成分种类及峰高均存在差异;综合聚类分析能将不同规格怀牛膝区分开。结论不同规格怀牛膝内部质量存在差异;实验中所建立的HPLC指纹图谱可以全面反映不同规格怀牛膝的化学成分分布,为不同规格怀牛膝的整体质量评价提供参考。  相似文献   
3.
L. Abrahamsson  H. Hackl 《Maturitas》1981,3(3-4):225-234
53 patients from a mainly climacteric population were treated monthly with 200 mg dehydro-epiandrosterone (DHEA) oenanthate or with 1 ampoule Gynodian-Depot®. Pronounced adiposity was present in 15 of these cases. Hormonal variables were determined before the treatment and during the depot effect of the preparations in order to study the principle which supports the oestrogenic influence and any weight-reducing influence under administration of DHEA. The elimination of lowpolar oestrogens increased considerably in 4 out of 13 post-menopausal cases treated with DHEA. This effect is probably indirect and presupposes intact ovaries. The incorporation of exogenous DHEA into the excretion of 17-ketosteroids and of 17-ketogenic steroids, such as those of androsterone + aethiocholanolone, depends on the size of the initial pool inasmuch as it is higher in small initial pools than in saturated pools - the size of the pool being age-dependent.

An average weight loss of >1 kg/mth was observed under DHEA treatment in 7 out 15 adipose cases. In comparison to the other 8 adipose cases, these 7 were younger and therefore also displayed higher values for 17-ketosteroids and their individual fractions. These circumstances appeared to explain why the administration of DHEA resulted in higher levels of free plasma DHEA which, in contrast to the cases without loss of weight, also resulted in an increase of renal DHEA-sulphate clearance. It was concluded from the findings that this is the explanation for the catabolic effect of exogenous DHEA.

Post-menopausally increased FSH and LH fractions were markedly suppressed in about half of the determinations after Gynodian-Depot administration, the findings indicating that DHEA is probably involved in suppression of the LH fraction.  相似文献   

4.
为探讨职业性接触苯、甲苯、二甲苯对子代行为的影响,以46名父母生育期接触苯、甲苯、二甲苯的儿童为暴露组;抽取与暴露组同年龄、同性别、同班级、其父母无任何职业有害因素接触史的58名儿童为对照组,用WICS-R(韦克斯勒儿童智力量表)对研究对象进行智力测验,用NB-I型视运动反应仪测试视简单反应时。结果显示,接触组各智力测验的得分均低于对照组,视反应时指标慢于对照组,差异有显著意义;进一步的分层分析结果显示,母接触组的各项得分均低于对照组,而父接触组的各项得分与对照组之间差异无显著意义。  相似文献   
5.
以氯化亚铁和甘氨酸为原料,研究了甘氨酸螯合铁的合成工艺条件.结果表明,pH值、配位比以及抗氧化剂用量对产品组成和得率有很大影响.确定了螯合的最适条件为:pH值为5.5、配位比为4∶1.采用有机溶剂萃取法,使甘氨酸螯合铁在无水乙醇中以沉淀的方式析出,实现甘氨酸螯合铁与无机铁的分离.讨论了萃取时有机溶剂用量对产品得率的影响,在无水乙醇与滤液的体积比为9∶1时,亚铁得率最高.  相似文献   
6.
修订车间空气中溶剂汽油容许浓度的研究   总被引:1,自引:0,他引:1  
通过对969例汽油作业工人的体格检查和对86个作业点760次车间内汽油浓度的测定结果表明,在达标的条件下,工人仍有神经衰弱,植物神经功能障碍的临床症状,说明现行车间的卫生标准应当进行修订。根据动物实验资料计算 MAC,180汽油为198.6mg/m~3,120汽油为225.0mg/m~3,二者相差不大,我们建议车间空气中溶剂汽油容许浓度可修订为200mg/m~3。  相似文献   
7.
分别用聚二醇,1-2丙醇,无水乙醇与水组成不同比例的二元溶剂系统,测定了弱极性药物SMZ及TMP在上述各系统中的溶解度。从而导出药物溶解度与二混合溶剂体积分类间的半实验方程。  相似文献   
8.
During growth of the blastocyst there is a net flow of cells from the polar to the mural trophectoderm which is presumed to be radially symmetrical. However, such a pattern of cell movement is inconsistent with findings from a recent clonal analysis. To visualize the overall flow of cells directly, the polar trophectoderm of expanding blastocysts was labelled globally with fluorescent microspheres. Following further growth, the great majority of blastocysts that remained labelled throughout the polar trophectoderm exhibited a polarized rather than radial spread of label into the mural region. This was the case regardless of the labelling technique, whether the blastocysts were grown in utero or in vitro, or had the zona pellucida removed or left on. Intriguingly, where there were two foci of spread of label into the mural trophectoderm rather than one, these were diametrically opposite each other. In further experiments, fluorescent lineage labels were used to distinguish junctional trophectoderm cells with and without an extension onto the blastocoelic surface of the inner cell mass. The location of clones formed following further blastocyst growth provided no evidence that egress of cells from the polar trophectoderm is restricted circumferentially by the presence of junctional cells having an extension.  相似文献   
9.
研究四种类型热塑性聚合物的6种常见医用输液接头材料对抗肿瘤药物溶剂的耐受性。将这些材料的标准测试样条固定在弯曲应变为1.5%的自制夹具上,分别浸泡在Etoposide?药物溶剂、Busulflex?药物溶剂或DMSO(以50%为例)等3种抗肿瘤药物溶剂,然后观察试样的外观,测试试样的拉伸强度、断裂伸长率和缺口冲击强度等性能的变化情况,采用定量化的评分,对6种材料的抗肿瘤药物溶剂的耐受性进行了评价。结果表明,两款超硬质热塑性聚氨酯(TPU)材料对三种抗肿瘤药物溶剂的耐受性均优于其他4种评价的材料,为接触抗肿瘤药物类的医疗器械产品的较优选择,比如PICC,CVC,输液器等。  相似文献   
10.
CORDIC算法在B超数字扫描变换器中的应用   总被引:1,自引:0,他引:1  
数字扫描变换器在B型超声诊断仪的应用,能使现代实时B型超声诊断仪实现一些新的诸如图像冻结、多帧贮存、数据测量计算和TV显示等功能。在设计B型超声诊断仪中数字扫描变化器的过程中,直角坐标到极坐标变换是一个关键的技术,本研究论述了应用在数字扫描变化器中的一种新的算法——CORDIC算法,对该算法的原理进行了简介,将CORDIC算法应用到直角——极坐标变换中,并进行了算法修正和公式计算。根据其具体的应用对该算法进行了优化,并给出了算法的硬件实现结构。最后,对算法进行了软件仿真,并给出了结果分析。  相似文献   
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