Studies on the interaction of p-phenylene diamine with phospholipids

In vitro studies on the interaction of phospholipids with p-phenylene diamine, a major component of hair dyes, were undertaken. Thin layer and molecular sieving chromatography along with phosphorus estimation and spectral characterization suggested the possibility of p-phenylene diamine and its biotransformation products combining with lipophilic biomolecules.     

Percutaneous absorption of p-phenylene diamine during an actual hair dyeing procedure

An analytical method has been developed that allows the determination of p-phenylene diamine derivatives in urinary samples collected from women after hair dyeing with commercial formulations. During an on-line flash hydrolysis of the urine, a number of metabolites of p-phenylene diamine were hydrolyzed to free p-phenylene diamine, which was then determined using gas chromatography-mass spectrometry. The excretion of metabolites of p-phenylene diamine could be followed during 24 or 48 hours after the dye had been applied. Most of the p-phenylene diamine cleaved by the flash hydrolysis procedure was, in fact, involved in the N,N'-diacetyl combination. The dose excretion for p-phenylene diamine as measured by this method was comparable to that found by other authors who made use of radioactively labelled material. The present analytical method can be used to evaluate procedures intended to decrease the percutaneous absorption of p-phenylene diamine. Thus, a five- to ten-fold decrease in its penetration was observed by protecting the scalp with clay before applying the dyeing composition.     

Formulation effects of topical emulsions on transdermal and dermal delivery

It has been recognized that the vehicle in which a permeant is applied to the skin has a distinctive effect on the dermal and transdermal delivery of active ingredients. The cutaneous and percutaneous absorptions can be enhanced, e.g. by an increase in thermodynamic activity, supersaturation and penetration modifiers. Furthermore, dermal and transdermal delivery can be influenced by the interactions that may occur between the vehicle and the skin on the one hand, and interactions between the active ingredient and the skin on the other hand. Emulsions are widely used as cosmetic and pharmaceutical formulations because of their excellent solubilizing capacities for lipophilic and hydrophilic active ingredients and application acceptability. This review focuses, in particular, on the effect of emulsions on the dermal and transdermal delivery of active ingredients. It is shown that the type of emulsion (w/o vs. o/w emulsion), the droplet size, the emollient, the emulsifier as well as the surfactant organization (micelles, lyotropic liquid crystals) in the emulsion may affect the cutaneous and percutaneous absorption. Examples substantiate the fact that emulsion constituents such as emollients and emulsifiers should be selected carefully for optimal efficiency of the formulation. Moreover, to understand the influence of emulsion on dermal and transdermal delivery, the physicochemical properties of the formulation after application are considered.     

Epidermal and dermal changes in response to various skin rejuvenation methods

During the last years, a number of new devices have been developed to improve the dermal and epidermal signs of photo‐ and chronological skin ageing. There are well‐established ablative and non‐ablative skin resurfacing options using different lasers and light sources, but side effects have been observed frequently. A recently developed photorejuvenation method using non‐thermal stimulation of skin cells with low energy and narrow band light has been termed photomodulation. Light emitting diodes are the ideal source of this kind of light that stimulate mitochondrial cell organelles leading to up‐regulation of cytochrome electron transport pathway leading to mitochondrial DNA gene modulation. This paper reviews the most current knowledge of intrinsic and extrinsic changes of ageing and summarizes different systems for skin rejuvenation with focus on non‐thermal non‐ablative skin rejuvenation modalities.     

多轴向导电芳纶增强复合材料及其电磁屏蔽性能

为提高芳纶的导电能力,以芳纶长丝纱为基材,采用一种基于原位聚合法的纱线连续导电处理方法制备芳纶/聚苯胺复合导电纱线。并以导电芳纶为增强体,以不饱和聚酯树脂为基体,制备了二轴向、三轴向和四轴向导电芳纶增强复合材料,研究了其电磁屏蔽性能。结果表明:经导电处理后,芳纶纤维表面附着一层导电聚苯胺,其电导率可达1.4~1.9 S/cm,力学性能稍有下降;多轴向导电芳纶增强复合材料其屏蔽效能值随着导电芳纶轴向数和排列密度的增大而提高,当导电芳纶排列密度达到70 根/(5 cm)时,四轴向导电芳纶增强复合材料对0.1~1.5 GHz范围内电磁波的平均电磁屏蔽效能达到22 dB。     

壳聚糖固定化树莓超氧化物歧化酶的研究

研究壳聚糖固定化超氧化物歧化酶的酶学性质。分别以不同方法对超氧化物歧化酶进行固定并比较其活力,对固定化方法进行相应的优化,对固定化超氧化物歧化酶进行酶学性质测定。结果表明,以壳聚糖为载体,戊二醛交联法制备固定化超氧化物歧化酶,优化条件下制备的固定化酶,所得壳聚糖酶粉活力为192U/g,酶活回收率为34%,热稳定性和酸碱稳定性较游离酶有很大的提高,且具有良好的贮存稳定性,固定化酶粉可实现反复使用,提高了利用率。壳聚糖-戊二醛交联法可用于制备性能较优的固定化超氧化物歧化酶。     

蔗渣浆OHMP漂白废水的毒性及毒性污染负荷的研究

采用发光细菌法对蔗渣浆OHMP漂白废水进行了毒性研究,实验结果表明,O段废水的EC50为330%,属于无毒级别;H段废水的EC50为203.8%,属于无毒级别.整个漂白工艺过程排放的毒性因子(TEF)为54.776TU·m3/t浆,其中O段废水的TEF为1 8.786TU·m3/t浆,占总量的34.3%,H段废水的TEF为35.99TU·m3/t浆,占总量的65.7%.蔗渣浆OHMP漂白工艺毒性排放当量相当于5.477gHgCl2/t浆,毒性当量较小.     

芹菜素的急性毒性、遗传毒性及亚慢性毒性试验研究

目的 研究芹菜素的安全性,为其合理开发利用提供科学依据.方法 根据《食品安全性毒理学评价程序和方法》,进行了芹菜素急性毒性试验、小鼠骨髓微核实验、Ames试验、小鼠精子畸变试验、大鼠90天喂养试验.结果 芹菜素大鼠急性毒性的MTD大于8 g/kg BW,遗传毒性试验结果为阴性,未见芹菜素对大鼠体重、摄食量、食物利用率、血常规、血生化、尿常规有生物学意义的影响.芹菜素对大鼠脏器无明显影响.结论 芹菜素属实际无毒物,无遗传毒性,芹菜素的大鼠90天喂养实验的NOAEL为8 g/kg BW.     

超氧化物歧化酶研究与应用

超氧化物歧化酶(superoxide dismutase SOD)是一种专一清除超氧阴离子自由基(O2.-)的金属蛋白酶,催化超氧阴离子自由基O2.-发生歧化反应,从而清除O2.-,具有抗炎,抗病毒,抗辐射,抗衰老等作用。对SOD的来源分布、提纯方法、化学修饰、活性测定和生产应用等方面进行了综述,并对其生产问题以及应用前景进行了分析。     

鸡卵清白蛋白多肽抗皮肤光老化的功能研究

本文以昆明小鼠和鸡卵清白蛋白多肽为研究对象,研究了鸡卵清白蛋白多肽对紫外线损伤的小鼠光老化皮肤的保护作用。实验动物随机分为正常对照组、模型对照组、Vc阳性对照组、卵清白蛋白多肽低剂量组、卵清白蛋白多肽高剂量组五组。除正常对照组外,运用紫外灯管模拟紫外线长期照射各组小鼠皮肤的无毛部分,建立小鼠皮肤光老化模型。同时,用5％Vc溶液、10％的鸡卵清白蛋白多肽溶液、40％的鸡卵清白蛋白多肽溶液分别外涂于Vc阳性对照组、卵清白蛋白多肽低剂量组、卵清白蛋白多肽高剂量组小鼠背部无毛皮肤,正常对照组和模型对照组涂抹蒸馏水。60天后,观察各组小鼠皮肤的表观特征并测定相关生化指标。结果显示,与模型对照组相比,鸡卵清白蛋白多肽高、低剂量组小鼠皮肤光滑,褶皱较浅,富有弹性,红斑极少,接近正常对照组小鼠皮肤;皮肤重量均显著降低（p〈0．01,p〈0．01）,羟脯氨酸（HPY）含量均显著降低（p〈0．01,p〈0．05）,丙二醛（MDA）含量存在显著差异（p〈0．05,p〈0．05）,超氧化物歧化酶（SOD）活力显著增强（p〈0．05,p〈0．05）。说明鸡卵清白蛋白多肽对小鼠光老化皮肤有明显的保护作用。     

大蒜细胞溶质中超氧化物歧化酶的性质研究

利用热变性、等电点沉淀和DEAE -纤维素柱层析分离纯化大蒜细胞溶质中的超氧化物歧化酶 ,并对其性质进行了研究。结果表明 ,温度 40～ 6 0℃、pH4～ 9范围内酶的活性稳定 ,对KCN和H2 O2 敏感 ,紫外光区的吸收峰在 2 5 8nm ,可见光区的吸收峰在 6 80nm ,表明酶的类型为Cu·Zn SOD。     

大蒜细胞溶质中超氧化物歧化酶的性质研究

利用热变性、等电点沉淀和DEAE-纤维素柱层析分离纯化大蒜细胞溶质中的超氧化物歧化酶(Superoxidedismutase,SOD),并对其性质进行了研究。结果表明:温度40～60℃、pH4～9范围内酶的活性稳定对KCN和H2O2敏感紫外光区的吸收峰在258nm,可见光区的吸收峰在680nm,表明酶的类型可能是Cu·Zn-SOD。     

仙人掌SOD提取条件及提取过程活性稳定性研究

以新鲜仙人掌为材料,采取直接打浆浸提的方式,提取仙人掌SOD。中性偏碱的缓冲液在30～35℃浸提效果较好。仙人掌SOD在60℃以下稳定性较强,可以采用55～60℃加热10～15min处理去除部分杂蛋白。V(二氮甲烷):V(乙醇)=2:1的比例处理SOD粗提液,也有利于去除杂蛋白,提高SOD比活性。仙人掌SOD在酸性条件下对紫外光敏感,碱性条件下对日光敏感,在pH 6～8对日光和紫外光都较稳定。     

Commonly used UV filter toxicity on biological functions: review of last decade studies

Sunscreens provide broad‐spectrum UV skin protection and contain more often UV filter combinations. Their efficacy reducing skin photo carcinogenesis and photo ageing is widely documented. However, there are many concerns about UV filter safety. Organic UV filters were the first targeted by scientist concerns, as they were showed to trigger skin allergic reactions. Inorganic UV filters were then at the heart of scientist debate especially because of their nanometric size. Over the last years, many studies have been published tending to highlight that organic as well as inorganic UV filters could lead to variable side effects after sunscreen application. However, these studies are still very controversial due to different experimental conditions and models. This review reveals that complementary studies using standardized methods are mandatory before ascertaining that UV filters threaten human health.     

酿酒酵母SOD1、SOD2基因缺失对胁迫耐受性的影响

以sod1Δ、sod2Δ、sod1Δsod2Δ酿酒酵母基因缺失菌株为遗传材料,采用休止细胞梯度生长法,分析SOD1和SOD2基因缺失对高温、乙醇毒性、高渗透压、高盐、乙酸毒性及营养饥饿胁迫条件耐受性的影响。结果显示,与野生型菌株相比,sod1Δ菌株对高温、高渗透压和乙酸胁迫的耐受性降低;sod2Δ菌株耐受性无明显变化;sod1Δsod2Δ双缺失菌株对高温、乙醇毒性、乙酸毒性、高渗透压和高盐的耐受性均下降,表明酵母超氧化物歧化酶基因与多种胁迫耐受性密切相关。     

Activation of fibroblast metabolism in a dermal and skin equivalent model: a screening test for activity of peptides

Skin firmness, elasticity and tone are gradually lost with age. These changes originate in the dermis and correspond to a decrease in the ability of cells, particularly the fibroblasts, to regenerate the molecules which make up the extracellular matrix. Skin ageing is also characterized by a reduction of the epidermal thickness and by a flattening of the basal membrane. The recent development of two 3-dimensional culture systems, in which the cells develop within a porous structure reproducing the extracellular matrix of the human dermis, is a way of reproducing in vivo conditions and demonstrating the biological effects of anti-ageing compounds. The dermal equivalent model used in this study is composed of a dermal matrix made of collagen-chitosan-glycosaminoglycans populated by normal human fibroblasts which synthesized their own extracellular matrix. A skin equivalent model is obtained by the cell culture of normal human keratinocytes onto a dermal equivalent elevated at the air-liquid interface. Such models were used to prove anti-ageing activity of promising compounds. Cosmetic Science has used many protein hydrolysates in order to fight skin ageing, but up to now, these natural peptides were poorly studied, and their efficacy poorly demonstrated. Eight protein hydrolysates were screened in a proliferation study in monolayered cultures giving two selected polypeptides. A soya derived peptide was used for an efficiency study in 3-dimensional models. In the dermal equivalent model, this peptide increased fibroblast proliferation by 40% and led to a stimulation of collagen formation (165%) and elastin (116%) synthesis. The effect of this soya peptide on glycosaminoglycan synthesis was also significant, with increases of 36% for chondroitin-4-sulfate and 68% for hyaluronic acid. These results were confirmed using a skin equivalent model. In this model, the soya peptide increased the thickness of the epidermis.     

合作研制药用超氧化物歧化酶回忆

目的对合作研制药用超氧化物歧化酶的技术内容加以概括报道,供参考借鉴。方法根据研制过程的资料整理。结果和讨论合作研制做了大量工作,有一定意义,可供参考。     

聚乙烯醇对芳纶复合纱聚苯胺导电层耐久性影响

为提高聚苯胺导电层与基材之间的黏结牢度,以聚乙烯醇为共混高聚物,通过连续原位聚合法在对位芳纶纱线表面形成聚乙烯醇/聚苯胺导电层,制备得到芳纶/聚苯胺/聚乙烯醇复合导电纱。分析了导电纱的结构与性能,并研究了聚乙烯醇对聚苯胺导电层耐水洗和耐磨性的影响。结果表明:适量添加聚乙烯醇有助于提高导电纱导电层的结构规整性及电导率,随着聚乙烯醇质量分数的提高,导电纱的电导率呈先上升后下降的趋势,当聚乙烯醇占苯胺的质量分数为4.30%时,制得的复合导电纱线的电导率最高,达到(1.120±0.198) S/cm;聚乙烯醇的添加和质量分数的提高,有助于聚苯胺导电层耐水洗性及在较小外力作用下的耐磨性的提高。