nonmetal

  • 文章类型: Journal Article
    防止意外怀孕是全球公共卫生政策的目标之一,以尽量减少对个人的影响。家庭,和社会。各种避孕制剂具有很高的有效性和接受度,包括宫内节育器,女性的荷尔蒙补丁,男性的避孕套和输精管切除术,在过去的几十年中被开发和采用。然而,避孕技术尚未取得重大突破,虽然相关的长期不利影响是无法克服的,如内分泌系统紊乱和激素给药,侵入性结扎,并在取出宫内节育器后缓慢恢复生育能力。受到纳米材料和生物技术发展的刺激,先进的避孕药可以通过更安全,更可控和有效的方法来满足不同生殖阶段男女的各种特殊需求。纳米医学技术已经扩展到开发避孕方法,例如女性使用纳米载体的靶向药物递送和激素的控制释放,以及男性通过光热治疗或磁性热疗使用功能性纳米材料的物理刺激辅助输精管切除术。用于高级避孕药的纳米材料解决方案提供了显着改善的生物安全性,非侵入性管理,和可控的可逆性。这篇综述总结了女性和男性避孕药的纳米材料解决方案,包括工作机制,临床关注,以及他们的优点和缺点。这项工作还回顾了在避孕应用中采用的纳米材料。此外,我们进一步讨论了纳米材料在下一代避孕药的纳米策略开发中的安全性考虑因素和未来前景.我们预计在不久的将来,纳米材料可能会取代传统的避孕材料。
    Preventing unintentional pregnancy is one of the goals of a global public health policy to minimize effects on individuals, families, and society. Various contraceptive formulations with high effectiveness and acceptance, including intrauterine devices, hormonal patches for females, and condoms and vasectomy for males, have been developed and adopted over the last decades. However, distinct breakthroughs of contraceptive techniques have not yet been achieved, while the associated long-term adverse effects are insurmountable, such as endocrine system disorder along with hormone administration, invasive ligation, and slowly restored fertility after removal of intrauterine devices. Spurred by developments of nanomaterials and bionanotechnologies, advanced contraceptives could be fulfilled via nanomaterial solutions with much safer and more controllable and effective approaches to meet various and specific needs for women and men at different reproductive stages. Nanomedicine techniques have been extended to develop contraceptive methods, such as the targeted drug delivery and controlled release of hormone using nanocarriers for females and physical stimulation assisted vasectomy using functional nanomaterials via photothermal treatment or magnetic hyperthermia for males. Nanomaterial solutions for advanced contraceptives offer significantly improved biosafety, noninvasive administration, and controllable reversibility. This review summarizes the nanomaterial solutions to female and male contraceptives including the working mechanisms, clinical concerns, and their merits and demerits. This work also reviewed the nanomaterials that have been adopted in contraceptive applications. In addition, we further discuss safety considerations and future perspectives of nanomaterials in nanostrategy development for next-generation contraceptives. We expect that nanomaterials would potentially replace conventional materials for contraception in the near future.
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  • 文章类型: Journal Article
    The safety of food is a matter of global concern today. Continuous monitoring of canned tuna and canned sardines quality is essential regarding metal, nonmetal, and metalloid content. In this article, we present the data on the elemental content obtained in canned tuna and canned sardines by using inductively coupled plasma optical spectrometry (ICP OES), as well as the data on Pollution Index (PI) and Health Risk Index (HRI). Pollution index and health risk index are tools used to assess elemental contamination in the environment and food. A total of 6 metals (Al, Ba, Ca, Cu, Fe, and Zn), one nonmetal (Se), and one metalloid (As) were quantified in the samples of the canned tuna and canned sardines. For elements as Al, Cu, Fe, and Se, PI > 1. In addition, Cd, Co, Cr, Ni, Zn, and Pb have PI values less than 1. The HRI values for some canned tuna samples were above 1 for elements such as Al, Ba, Ca, and As. For canned sardines, the elements Cr, Ni, and As showed HRI values >1.
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  • 文章类型: Journal Article
    This paper studied the influence of waste printed circuit boards (PCBs) characteristics and nonmetal surface energy (SE) regulation on flotation. First, SEM-EDS was applied to study the appearance and surface element distribution of the glass fiber and copper. The results showed that the glass fiber was present in a bundle and the surface carbon content was 49.42%, which facilitated glass fiber floating. The copper appearance contained many nodules, with a carbon content of 32.54%, which hindered copper sorting. XPS analysis further discovered that copper was mainly present in the forms of CuO, Cu(Met), and Al2Cu. A FT-IR analysis revealed that the organic matter in the PCBs was essentially the same as the epoxy resin. It was easy to achieve floating and some polar functional groups promoted the adsorption of the flotation reagents. Based on this, by calculating the nonmetal SE, it was found that the proportion of the non-polar component of the nonmetal SE was 94.60%. The EDLVO theory was applied to research interactions between nonmetal particles. Hydrophobic attraction was found to be the main factor causing nonmetal particles to agglomerate. Further, the tannin was used to improve the dispersion of nonmetal by adjusting the nonmetal SE. Furthermore, the hydroxyl and carbonyl groups in the tannin may form hydrogen bonds with the bromine, epoxy and hydroxyl groups in the nonmetal. Finally, flotation test results indicated that tannin added significantly enhanced PCBs flotation efficiency. When the amount of tannin added increased from 0 to 60 mg/L, the recovery of copper increased from 61.92% to 90.53%. Thus, this study provides an alternative approach to improve the flotation efficiency of waste PCBs.
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  • 文章类型: Journal Article
    This review covers the characterization and distribution of metals and nonmetals in the Alberta oil sands region (AOSR) of Canada. The development of the oil sands industry has resulted in the release of organic, metal and nonmetal contaminants via air and water to the AOSR. For air, studies have found that atmospheric deposition of metals in the AOSR decreased exponentially with distance from the industrial emission sources. For water, toxic metal concentrations often exceeded safe levels leading to the potential for negative impacts to the receiving aquatic environments. Interestingly, although atmospheric deposition, surface waters, fish tissues, and aquatic bird eggs exhibited increasing level of metals in the AOSR, reported results from river sediments showed no increases over time. This could be attributed to physical and/or chemical dynamics of the river system to transport metals to downstream. The monitoring of the airborne emissions of relevant nonmetals (nitrogen and sulphur species) was also considered over the AOSR. These species were found to be increasing along with the oil sands developments with the resultant depositions contributing to nitrogen and sulphur accumulations resulting in ecosystem acidification and eutrophication impacts. In addition to direct monitoring of metals/nonmetals, tracing of air emissions using isotopes was also discussed. Further investigation and characterization of metals/nonmetals emissions in the AOSR are needed to determine their impacts to the ecosystem and to assess the need for further treatment measures to limit their continued output into the receiving environments.
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  • 文章类型: Journal Article
    This study investigated the feasibility of using acrylonitrile-butadiene-styrene (ABS) waste plastic and nonmetal particles from waste printed circuit boards (WPCB) to manufacture reproduction composites (RC), with the aim of co-recycling these two waste resources. The composites were prepared in a twin-crew extruder and investigated by means of mechanical testing, in situ flexural observation, thermogravimatric analysis, and dimensional stability evaluation. The results showed that the presence of nonmetal particles significantly improved the mechanical properties and the physical performance of the RC. A loading of 30 wt% nonmetal particles could achieve a flexural strength of 72.6 MPa, a flexural modulus of 3.57 GPa, and an impact strength of 15.5 kJ/m2. Moreover, it was found that the application of maleic anhydride-grafted ABS as compatilizer could effectively promote the interfacial adhesion between the ABS plastic and the nonmetal particles. This research provides a novel method to reuse waste ABS and WPCB nonmetals for manufacturing high value-added product, which represents a promising way for waste recycling and resolving the environmental problem.
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