Sonochemical synthesis, characterization, antimicrobial activity and textile dyeing behavior of nano-sized cobalt(III) complexes

Occurrence and potential release of heavy metals in female underwear manufactured in China: Implication for women's health

Underwear is a potential source of women's exposure to heavy metals owing to its direct contact with the skin, especially the skin of the vagina and vulva, which has a strong absorptive capacity. However, information regarding the prevalence of metals in female underwear, and its potential hazards, remains scarce. In the present study, we examined the concentrations and potential release of Cr, Co, Ni, Cu, As, Cd, Sb, and Pb in brassieres and briefs manufactured in China. We detected higher levels of Pb and moderate levels of other metals, relative to the metal levels reported for other textiles in the literature. Cu, As, Ni and Cd, had higher migration rates (MRs) from the underwear, with medians of 100%, 100%, 30.1%, and 20.7%, respectively. The median MRs of the other metals were in the range 1.07%-15.7%. On the whole, the total and extractable concentrations of these metals differed by item and fabric type. The pollution of raw materials and the use of chemical additives containing metals commonly contributed to the metals in the underwear. On the basis of the exposure estimation, the non-carcinogenic risks posed by the underwear metals were acceptable, but the carcinogenic risks from the metals in 5.18% of brassiere samples exceeded the acceptable level.

Cobalt oxide nanoparticles: An effective growth promoter of Arabidopsis plants and nano-pesticide against bacterial leaf blight pathogen in rice

Recently, the application of cobalt oxide nanoparticles (Co₃O₄NPs) has gained popularity owing to its magnetic, catalytic, optical, antimicrobial, and biomedical properties. However, studies on its use as a crop protection agent and its effect on photosynthetic apparatus are yet to be reported. Here, Co₃O₄NPs were first green synthesized using Hibiscus rosa-sinensis flower extract and were characterized using UV-Vis spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction (XRD), transmission/scanning electron microscopy methods. Formation of the Co₃O₄NPs was attested based on surface plasmon resonance at 210 nm. XRD assay showed that the samples were crystalline having a mean size of 34.9 nm. The Co₃O₄NPs at 200 µg/ml inhibited the growth (OD₆₀₀ = 1.28) and biofilm formation (OD₅₇₀ = 1.37) of Xanthomonas oryzae pv. oryzae (Xoo) respectively, by 72.87% and 79.65%. Rice plants inoculated with Xoo had disease leaf area percentage (DLA %) of 57.25% which was significantly reduced to 11.09% on infected plants treated with 200 µg/ml Co₃O₄NPs. Also, plants treated with 200 µg/ml Co₃O₄NPs only had significant increment in shoot length, root length, fresh weight, and dry weight in comparison to plants treated with double distilled water. The application of 200 µg/ml Co₃O₄NPs on the Arabidopsis plant significantly increased the photochemical efficacy of PSII (ΦPSII) and photochemical quenching (qP) respectively, by 149.10% and 125.00% compared to the control while the non-photochemical energy dissipation (ΦNPQ) was significantly lowered in comparison to control. In summary, it can be inferred that Co₃O₄NPs can be a useful agent in the management of bacterial phytopathogen diseases.

Occurrence and health implications of heavy metals in preschool children's clothing manufactured in four Asian regions

Clothing may be a potential contributor to body metal burden in children. However, available information on heavy metals in children's clothing is extremely limited and the associated health risks remain poorly understood. This study investigated the concentrations of Pb, Cd, Co, Zn, Cr, As, Cu and Ni in new preschool children's clothing manufactured in four Asian regions. The children's clothing had higher levels of Ni and Cr but lower levels of Pb and Cd in comparison to the concentrations reported in other textile products. The concentrations of Cd were higher in the black clothing than those in the white and color samples. The non-cotton samples contained higher Co concentrations. The Pb concentrations in the samples manufactured in China were significantly higher than those in the other three regions. We estimated the dermal exposure doses for these metals and calculated the associated risks. The results indicated that the health risks from exposure to these metals in the children's clothing were acceptable. However, more research is required to investigate heavy metals and the associated risks in child clothing due to the increasing complexity of their materials and manufacturing processes.

An efficient ultrasonic-assisted bleaching strategy customized for yak hair triggered by melanin-targeted Fenton reaction

Promoting processing efficiency and taking advantage of agricultural by-products are two promising ways to achieve sustainable textile industry. This study presents a customized efficient ultrasonic-assisted bleaching strategy for yak hair - a widely existing but underexploited secondary dark shade fibre from yak. A melanin-targeted Fenton oxidation process is established which involves three phases, i.e., (I) incorporation of Fe²⁺ ions with melanin, (II) catalytic oxidative bleaching using hydrogen peroxide (H₂O₂), and (III) reductive cleansing. The bleaching efficacy, dyeing performance and tensile property of yak hair treated with and without ultrasound were explored and compared. Further, the ultrasonic bleaching mechanism in terms of the catalytic effect of Fe²⁺ ions, the promotion of H₂O₂ decomposition, removal of melanin granule from yak hair, were demonstrated. Finally, the main effects and interactions of parameters in phase II, and optimal condition were obtained through mathematical modelling based on a central composite design (CCD). Results reveal that ultrasonic bleaching dramatically enhances the whiteness index (WI) of yak hair from 11 to 45 which is 44.6% higher than those bleached without ultrasound, and also promotes the uptake of acid dyes. There is only 15% tensile strength loss and 14% elongation increment of yak hair after ultrasonic bleaching, rising from a slight damage of cuticle layer and cleavage of disulfide bonds, respectively. In the study of bleaching mechanism, Fe²⁺ ion is confirmed to improve the H₂O₂ decomposition rate by 20.9% which further runs up to 35.9% after introducing ultrasound. Ultrasound increases the concentration of hydroxyl radicals (HO) by 94% which are the main oxidative species participating in bleaching confirmed by HO scavenging experiment. The porous structure was observed on the cross section of yak hair stemming from the removal of melanin granules contributed by the cleaning action of ultrasound. A theoretical highest WI of 52.4 can be achieved under an optimal condition based on the CCD study. In general, the proposed melanin-targeted bleaching strategy for yak hair that integrates ultrasonic technology and Fenton reaction, is beneficial to the development of sustainable textile industry from material and processing perspectives.

Synthesize and multi-spectroscopic studies of zinc-naproxen nanodrug as DNA intercalator agent

The zinc-naproxen complex as a nano-drug (NanoD) was synthesized successfully via fast and effective ultrasound-assisted processes. The chemicophysical properties of the NanoD were determined using FT-IR, XRD, SEM, and EDX mapping analyses. The results confirmed the formation of the 55 nm NanoD laminates. The interaction of the obtained NanoD with calf thymus deoxyribonucleic acid (CT-DNA) was studied as well. Structural and topography changes of DNA in interaction with the NanoD were investigated by atomic force microscopy (AFM). The results of electronic absorption spectroscopy, the DNA-viscosity studies, and competition fluorescence spectroscopy showed that CT-DNA binds to the NanoD through the intercalative binding mode. The data of AFM analysis indicated swollen CT-DNA upon interaction with the NanoD. The in vitro investigation of cytotoxicity of the NanoD on HT-29 and Hep G2 cancer cells demonstrated high cytotoxicity activity of the NanoD than that of cisplatin in HT-29 cell line, especially at lower concentrations.

Self-assembly of red-blood-cell-like (NH4)[Fe2(OH)(PO4)2]·2H2O architectures from 2D nanoplates by sonochemical method

Red-blood-cell-like (RBC-like) (NH₄)[Fe₂(OH)(PO₄)₂]·2H₂O architectures assembled from 2D nanoplates are successfully synthesized via a facile sonochemical method. XRD measurement indicates that the as-prepared sample is well crystallized with a monoclinic structure. The morphology of the sample is characterized by SEM analysis, which shows that the (NH₄)[Fe₂(OH)(PO₄)₂]·2H₂O particles exhibit a unique biconcave red blood cell morphology with an average diameter of 4um and thickness of 1.5um. The detailed time-dependent experiments are conducted to investigate the morphological evolution process. It reveals that the ultrasonic time is crucial to the morphology of the products, and the RBC-like (NH₄)[Fe₂(OH)(PO₄)₂]·2H₂O proceeds in steps of crystallization, formation of thin plates, and the subsequent self-assembly. Compared to the available methods that are typically time-consuming and complicated, this smart sonochemical strategy proposed herein is efficient and simple. Moreover, these obtained special RBC-like architectures will be more fascinating for application in many areas.