吡硫翁锌作为去屑剂的研究进展

吡硫翁锌(Zinc pyrithione,ZPT)作为去屑剂已被广泛应用于各类洗发产品中。综述了其作为去屑剂的作用机制,包括抑菌作用、抗代谢作用和皮肤表面的驻留机制,同时总结了国内外对ZPT的毒性研究报道,包括急毒性、水生生物胚胎毒性以及基因毒性报道。另外,对ZPT现有的检测方法,包括高效液相色谱法、滴定法和电化学方法等进行了总结分析。     

Disposition of zinc pyrithione in the rat

The pharmacokinetic profile of orally administered [2,6-¹⁴C]-labelled zinc pyrithione (ZPT) was defined in male and female rats and was used to predict the blood concentrations of ¹⁴C at steady state correlating with the skeletal-muscle weakness observed in long-term feeding tests and mechanism studies. The ¹⁴C concentration was determined in blood, urine and faeces as a function of time following oral administration of doses of 0·5, 1·25 and 12·5 mg [¹⁴C]ZPT/kg. The major route of elimination from the body was the urine, in which all the ZPT appeared as metabolites. Mass-spectroscopic analysis of the urine indicated that a minor metabolite was 2-mercaptopyridine-N-oxide and the major metabolites were S-glucuronides of 2-mercaptopyridine-N-oxide. Radioassay of tissues indicated that ZPT was rapidly excreted and was not retained in the body to any significant degree. A two-compartment open model was used to describe the dynamics of ZPT in males and females given 0·5, 1·25 or 12·5 mg/kg. Kinetic constants for the same dose indicated sex differences in plasma elimination, renal clearance, time required for attainment of maximum blood concentration and rate of absorption. The ratio for ¹⁴C binding in red blood cells and plasma, respectively, was 5:1 at 96 hr and increased to ⩾ 45:1 at 240 hr, a probable reason for the low renal clearance rates. No sex difference in the concentration of ¹⁴C in blood at steady-state levels (maximum and minimum) was seen with the 0·5 mg/kg dose, but a significant difference was apparent at 1·25 mg/kg, the concentration being higher in the females. The significantly lower blood concentration of ¹⁴C in the males, in conjunction with the apparent higher rate of metabolism in the male, provide a reasonable explanation for the demonstrated sex difference in the dietary level of ZPT capable of producing an effect.     

去屑香波中吡啶硫酮锌的沉积机理研究

通过测试去屑香波的絮胶形态、皮肤上吡啶硫酮锌(ZPT)的沉积量及漂白头发的梳理性,对比不同阳离子聚合物和硅油粒径大小对ZPT的覆盖均匀程度和沉积量的作用效果。研究发现:体系中由于同时存在小粒径硅油(SPS)和ZPT的过度积聚,大部分阳离子聚合物不适用于SPS去屑香波中,而改性瓜儿胶由于其特殊的表面处理,不会形成过度絮胶,适用于SPS去屑香波,保证ZPT有效沉积并提供优越调理性;而含大粒径硅油(LPS)的去屑香波中ZPT有效沉积与阳离子聚合物的电荷密度和分子量成正比。     

Dependence of zinc aluminate microscopic structure on its synthesis

Alumina doped with zinc oxide was synthesized by sol–gel method in alcohol solution. Hybrid oxides of aluminum and zinc were prepared from various aluminum precursors (aluminum sec-butoxide, aluminum nitrate, and aluminum isopropoxide) and zinc acetate solution with ethylacetoacetate and nitric acid as a chelating agent and catalyst, respectively. Types and molar ratio of the precursor to the chelating agent and acidic catalyst were found to remarkably affect the formation of transparent sol of aluminium–zinc sol composite. With relatively low temperature of 50 °C, the suitable molar ratio of aluminum sec-butoxide to ethylacetoacetate to nitric acid for preparing the homogeneous sol was 1:0.40:0.86. Furthermore, the calcination at elevated temperature higher than 400 °C would be essential for preparing ZnAl₂O₄ with the face centered cubic microstructure. The primary crystalline size of the synthesized zinc aluminate nanostructure was approximately 20 nm with lattice spacing of 0.55 nm.     

Boron uptake and toxicity in wheat in relation to zinc supply

Zinc deficiency may enhance B absorption and transport to such an extent that B may possibly accumulate to toxic levels in plant tops. Therefore, a screen house experiment was conducted to investigate the effect of B levels (0, 2.5, 5.0, 7.5 and 10 mg B kg^–1 soil) as influenced by Zn levels (0, 10 and 20 mg Zn kg^–1 soil) on DM yield of wheat tops and tissue concentration and uptake of B, Zn, Cu, Mn, Fe, Ca, Mg, K and P. Application of B decreased the dry matter yield of wheat significantly at all levels of Zn. Conversely, increasing levels of Zn increased the wheat yield significantly. The application of B increased the tissue concentration and uptake of B by wheat plants more in the absence than in the presence of Zn application. Consequently, concentration of B in wheat plants decreased with increasing levels of Zn application to the soil. This decrease in tissue B concentration was not only due to increased growth of wheat plants. Zinc application appears to have created a protective mechanism in the root cell environment against excessive uptake of B, as evidenced by the reduction of B uptake in Zn treated plants. The uptake of Mn, Mg and P decreased while the uptake of Cu, Fe, and K by wheat plants increased with Zn application. Whereas, the uptake of all nutrients (Cu, Fe, Mn, Ca, Mg, K and P) decreased significantly with the application of B. However, this depressive effect of B on nutrient uptake was less marked in the presence of applied Zn.     

Quantitative assessment of natural toxicity in sponges: toxicity bioassay versus compound quantification

Microtox^® assay was used to assess the natural toxicity of two sponges, Dysidea avara and Ircinia variabilis. The activity of crude extracts and major metabolites were compared. Methanol extract of D. avara was more toxic than that of acetone and was as toxic as pure avarol, thus suggesting that the toxicity of the sponge was mainly due to this metabolite. We also quantified palinurin, the major metabolite of I. variabilis, in specimens from several habitats. With the same methanol extracts used for palinurin quantification, we ran the Microtox^® assay and found a positive significant regression between toxicity and concentration of this metabolite. Pure palinurin was tested at the same concentration present in the extract, and the toxicity recorded was higher than that of the methanol extract. As with avarol from D. avara, palinurin is the main secondary metabolite that confers toxicity to I. variabilis. The results confirm that the standardized Microtox^® assay is an accurate and reproducible tool for assessing the toxicity of crude extracts and pure metabolites of marine organisms. These results also suggest that methanol is more suitable than acetone for the detection of species toxicity by Microtox^® The method is faster and easier to perform than chemical quantification even when the sponge chemistry is known, and is appropriate for studies on variation in natural toxicity over a range of environmental conditions.     

In vitro assessment of zinc apatite coatings on titanium surfaces

In this paper, coatings of hydroxyapatite partially substituted with zinc (ZnHA) were produced on titanium substrates by a two-step hydrothermal process using a precursor solution rich in calcium, phosphate and zinc. Activation of titanium surfaces was performed by oxidation with an acidic HF/HNO₃ solution. The coated substrates were then converted into HA by immersion in an alkali 0.1 M NaOH solution. The ZnHA samples were characterized by several techniques and their in vitro behavior was studied in comparison to hydroxyapatite (HA) and titanium (Ti-control) samples. A uniform and homogeneous calcium-deficient carbonate apatite coating was obtained for all samples, both doped and undoped with zinc. The percentage of zinc incorporated in the coatings is 7 at%, and the Ca/P ratio is 1.61(±0.01) for both types of samples, suggesting that Zn is incorporated substitutionally, replacing Ca atoms into the HA structure. The incorporation of Zn in the HA structure changed the crystals morphology, reduced crystals sizes and decreased the deposition rate showing that zinc is an inhibitor of the growth of HA crystal. X-ray diffraction showed that HA is the single crystalline phase present after alkali treatment. The coating adhesion strength was evaluated in terms of the critical load (Lc) obtained from scratch tests and no significant difference was found between the two tested groups, indicating the good adhesion of ZnHA to Ti substrates. The in vitro response of human osteoblasts (HOB) exposed to the surfaces of HA and ZnHA coatings was evaluated. The results of Live/Dead tests showed cell viability for all samples surfaces, but the adhesion and proliferation tests showed that ZnHA samples presented better adhered and spread cells compared with HA. ZnHA coatings presented cells with elongated or polygonal shapes and clearly more spread than HA. Quantitative analysis showed that there was a significantly higher number of cells adhered to ZnHA coatings compared to HA, indicating the zinc incorporation stimulates osteoblast proliferation.     

固体废物焚烧灰渣毒性评估及其控制方法研究进展

固体废物焚烧产生的灰渣时环境是一种二次污染物,其中,焚烧飞灰因其含有重金属及有毒有机污染物而被列为危险固体废物,因此在其最终处置前,必须进行稳定化处理.作者介绍了灰渣的污染特性,尤其是飞灰中所含重金属、有毒有机污染物的毒性及其各种评估方法,包括水平震荡法、浸出柱实验法、毒性浸出程序(TCLP),并综述了当前灰渣的控制技术方法和资源化利用手段,如水泥固化法、熔融固化法、化学药剂固化法.     

Physical assessment of toxicology at nanoscale: nano dose-metrics and toxicity factor

In this work, we propose a systematic and reproducible evaluation of nanoparticles (NPs) toxicology in living systems, based on a physical assessment and quantification of the toxic effects of NPs by the experimental determination of the key parameter affecting the toxicity outcome (i.e., the number of NPs) and of the NPs "toxicity factor". Such a strategy was applied to a well determined scenario, i.e., the ingestion of citrate-capped gold NPs (AuNPs) of different sizes by the model system Drosophila melanogaster. Using these AuNPs as a reference toxicity standard, we were able to define different regions in the multiparametric space of toxicity, enabling the classification of the toxic levels of other nanomaterials, such as quantum dots and pegylated AuNPs. This approach may pave the way to a systematic classification of nanomaterials, leading to important developments in risk assessment and regulatory approval, as well as in a wide range of nanomedicine applications.     

Rapid green-assisted synthesis and functionalization of superparamagnetic magnetite nanoparticles using Sumac extract and assessment of their cellular toxicity,uptake, and anti-metastasis property

Modifying the surface properties of superparamagnetic magnetite nanoparticles (SPMNPs) is essential for their stabilization and functionalization in biomedical applications. This study explored the use of Sumac (Rhus coriaria) plant extract as a green stabilizer for SPMNPs. Herein, we fabricated the aqueous colloidal suspension of SPMNPs via a facile and rapid green-assisted co-precipitation method using the extract solution as a green stabilizer (S_S), the results were then compared to the uncoated SPMNPs (S_B). Physicochemical properties of the as-synthesized NPs were characterized. The XRD planes of both samples matched the typical Fe₃O₄ NPs with a high degree of crystallinity. FESEM and TEM revealed that S_S were spherical and mono-dispersed with an average particle size of 11 nm, while the average particle size of S_B was measured to be around 9.9 nm. The elemental compositions of the S_S were approved by the EDX technique. FTIR and TGA results confirmed the presence of functional groups in the extract components and their interactions with SPMNPs. Based on the DLS analysis, Sumac extracts significantly prolonged the stability and increased the zeta potential value of the SPMNPs nanofluid from ?28.2 to ?44.8 mV. The magnetization (Ms) values of S_B and S_S samples were found to be 62.95 emu/g and 139.56 emu/g, respectively. VSM results pointed out that Sumac extracts dramatically enhanced the saturation magnetization of the coated SPMNPs. In vitro cytotoxicity and scratch assays of the S_S against MCF-7 cells indicated the non-toxicity, proliferation modulation, and growth inhibition abilities (anti-metastatic properties) of the modified NPs. In addition, the cellular uptake assessment of S_S on the MCF-7 cancer cell line revealed a dose-dependent internalization. Our findings implied that this hydrophilic, highly magnetic, stable, and biocompatible S_S is probably capable of being used in a wide range of biomedical applications such as MRI, magnetic hyperthermia, and cancer treatment.     

新型、高效、无毒的钙皂、锌皂热稳定剂的研究

通过静态及动态的热稳定实验来评价新型钙皂、锌皂热稳定剂的稳定效果。研究结果表明：这种新型钙皂、锌皂具有较高的热稳定效果,在１７０℃下的热稳定时间是硬脂酸钙硬脂酸锌的２倍以上,完全可以替代热稳定效果较差的硬脂酸钙、硬脂酸锌,可用于无毒ＰＶＣ制品中,具有良好的经济效益及社会效益。     

An assessment of zinc oxide nanosheets as a selective adsorbent for cadmium

Zinc oxide nanosheet is assessed as a selective adsorbent for the detection and adsorption of cadmium using simple eco-friendly extraction method. Pure zinc oxide nanosheet powders were characterized using field emission scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy. The zinc oxide nanosheets were applied to different metal ions, including Cd(II), Cu(II), Hg(II), La(III), Mn(II), Pb(II), Pd(II), and Y(III). Zinc oxide nanosheets were found to be selective for cadmium among these metal ions when determined by inductively coupled plasma-optical emission spectrometry. Moreover, adsorption isotherm data provided that the adsorption process was mainly monolayer on zinc oxide nanosheets.     

火焰原子吸收光谱法测定婴儿奶粉中锌含量的不确定度评定

建立了原子吸收光谱法测量奶粉中锌含量的不确定度评定方案,合理地赋予被测量值的分散性。本文根据JJF1059-1999技术规范要求,以AAS法测定婴儿奶粉中锌含量为例,全面分析了测量过程中引起不确定度的各种因素,并评估各不确定度的分量,计算得到合成标准不确定度和计算扩展不确定度,以不确定度的形式报告测量结果。本例的相对标准不确定度为5.4%,扩展不确定度为0.42mg/100g,测量结果为(3.90±0.42)mg/100g。评定方案适用于AAS法测定食品中锌、铁等金属离子含量的不确定度评估。     

Emerging Roles of Type-I Interferons in Neuroinflammation,Neurological Diseases,and Long-Haul COVID

Interferons (IFNs) are pleiotropic cytokines originally identified for their antiviral activity. IFN-α and IFN-β are both type I IFNs that have been used to treat neurological diseases such as multiple sclerosis. Microglia, astrocytes, as well as neurons in the central and peripheral nervous systems, including spinal cord neurons and dorsal root ganglion neurons, express type I IFN receptors (IFNARs). Type I IFNs play an active role in regulating cognition, aging, depression, and neurodegenerative diseases. Notably, by suppressing neuronal activity and synaptic transmission, IFN-α and IFN-β produced potent analgesia. In this article, we discuss the role of type I IFNs in cognition, neurodegenerative diseases, and pain with a focus on neuroinflammation and neuro-glial interactions and their effects on cognition, neurodegenerative diseases, and pain. The role of type I IFNs in long-haul COVID-associated neurological disorders is also discussed. Insights into type I IFN signaling in neurons and non-neuronal cells will improve our treatments of neurological disorders in various disease conditions.